Daily Data Insights

Bite-sized insights on how the world is changing, published every weekday.

Japan’s birth rate dropped sharply in 1966, influenced by cultural beliefs

A line chart showing Japan's birth rate from 1950 to 2023. Highlighted is a sharp dip in 1966, where birth rate drops over 20%, from 18.5 to 14.5 births per 1000 people. In 1967 the line returns back to around 19 births per 1000 people.

Demographic trends, such as births and deaths, can be influenced by many factors. Wars or pandemics can lead to higher death rates, while lower child mortality and access to contraception reduce the number of births.

But specific cultural beliefs can also have a strong effect, as in Japan in 1966. As you can see in the chart, the UN estimates that births decreased by about 20% from 1965 to 1966.

The reason behind this drop is unusual. Children born in 1966 had the “fire horse” as their birth sign. According to astrological predictions, women born that year would grow up to have a particularly difficult and possibly violent character.

Families who either believed this, or wanted to avoid the risk of their daughters having difficulty in the marriage market, chose not to have children that year. Couples may have abstained or used contraception, and in addition, the induced abortion rate in 1966 was significantly higher than in the surrounding years.

The next year of the fire horse is 2026. With the decline of these beliefs in Japan, fewer arranged marriages (where the birth sign might be a significant factor), and generally declining birth rates, we are unlikely to see this sharp drop in births again.

Explore more data on births and fertility in our Population & Demography explorer

Europeans consume more milk and dairy products than in other regions

Bar chart showing milk consumption per person across regions. Europe is the highest, followed by North America. Asia and Africa are both below the global average.

On average, Europeans consume more dairy products than people in other regions.

This chart shows the milk supply per person in each of the world’s regions. This is based on data from the Food and Agriculture Organization of the United Nations. It’s based on supply — the amount of milk available for consumption. It includes consumer waste, so it is a bit higher than the amount that is consumed in the end.

As you can see, the per-capita supply for Europe is more than twice the global average. People across Africa and Asia consume far less.

These numbers include dairy products such as yogurt and cheese, based on how much milk is used to produce them.

Explore country-by-country data on milk supply →

People across developing regions are spending far more time in school than 20 years ago

A line graph titled "Regional trends in average years of schooling, 2000 to 2022" shows the average number of years that adults over 25 participated in formal education across different regions. The vertical axis represents years of schooling, ranging from 0 to 8 years, with marked lines at 2, 4, 6, and 8 years. The horizontal axis indicates the years from 2000 to 2022.

Four distinct data series are represented by colored lines: 

- **Latin America and the Caribbean** 
- **East Asia and the Pacific**  
- **South Asia** 
- **Sub-Saharan Africa** 

A note on the graph emphasizes that both Sub-Saharan Africa and South Asia have seen significant improvements in average years of schooling. The data source is indicated as the UNDP, Human Development Report (2024).
Four distinct data series are represented by colored lines: 

- **Latin America and the Caribbean** (purple line) shows a consistent increase, reaching just above 8 years in 2022.
- **East Asia and the Pacific** (blue line) gradually rises, reaching around 6 years in 2022. 
- **South Asia** (red line) increases to slightly below 6 years, reflecting slow growth over the years.
- **Sub-Saharan Africa** (green line) shows a gradual increase, with a 50% rise since 2000, adding about 2 years, reaching close to 4 years by 2022.

A note on the graph emphasizes that both Sub-Saharan Africa and South Asia have seen significant improvements in average years of schooling. The data source is indicated as the UNDP, Human Development Report (2024). The graph is licensed under Creative Commons Attribution (CC BY).

In 2000, adults in South Asia and Sub-Saharan Africa had, on average, fewer than five years of schooling. That’s not enough to complete primary education.

But, as the chart shows, a lot of progress has been made since then. Adults older than 25 have gained more than two additional years of schooling, a 50% increase since 2000.

Latin American and East Asian countries have also made substantial gains, starting from a higher baseline.

This data is about adults. Children today can expect many more years of schooling, showing just how much progress has been made.

Of course, simply being in school isn’t enough; kids also need to learn while they’re there. And while more years of schooling generally mean more learning opportunities, it’s important to remember that millions of children in these regions still aren’t in school at all.

Discover more insights on access to basic education

Since 2010, progress in primary school enrollment in Sub-Saharan Africa has stalled

Since 2010, primary school enrollment in Sub-Saharan Africa has stalled, and is still far behind the levels that North America and Western Europe achieved decades ago

Over the past two centuries, the global share of children enrolled in primary school has increased dramatically. In 1820, fewer than 1 in 20 children were enrolled in primary school. Today, the figure is nearly 9 out of 10.

Sub-Saharan Africa, in particular, made remarkable progress for several decades, with enrollment rising from 57% in 1985 to 77% by 2010. Yet, as the chart shows, progress has stalled in the past decade, plateauing just under 80%.

In North America and Western Europe, near-universal primary school enrollment was achieved by the mid-1900s, with rates consistently above 95% since 1985.

Explore how far the world has come in expanding access to basic education and how much further we have to go

Americans are now one-third less likely to die from cancer at the same ages as Americans in 1990

Cancer death rates rise sharply with age. So, as the population grows and ages, we would expect the rate of cancer deaths to rise.
If we look at how death rates have changed for people of the same ages, the picture looks different.
National data from the United States, which comes from the WHO Mortality Database, is shown in the chart.
You can see that the “crude death rate”, which doesn’t adjust for aging, shows a rise and modest decline in cancer death rates since 1950.
But the “age-standardized death rate” shows a significant decline since its peak in 1990; it has fallen by one-third. This means that, within the same age groups, people in 2021 had a cancer death rate one-third lower than those in 1990. In other words, at the same ages, people are one-third less likely to die from cancer.
This decline results from several factors: better screening and earlier diagnosis, medical advances in cancer treatments, and public health efforts to reduce risk factors, like smoking and exposure to carcinogens.

How has the risk of dying from cancer changed in the United States?

To understand this, we can look at national cancer death rates in the United States.

The gray line shows the crude rate, which is the rate of deaths from cancer per 100,000 people. It has risen between 1950 and 1990 and has fallen slightly since then.

However, cancer death rates rise sharply with age, and the age of the US population has increased since 1950, so we would expect cancer death rates to rise for that reason alone.

What if we adjust for the increased age of the US population?

The red line, the age-standardized rate, shows this. It shows the cancer death rate if the age structure of the US population was held constant throughout.

This shows a slight rise until 1990 and then a significant decline; rates have fallen by one-third.

This means Americans are now one-third less likely to die from cancer at the same ages as Americans in 1990.

This comes from several factors: better screening and earlier diagnosis, medical advances in cancer treatments, and public health efforts to reduce risk factors like smoking and exposure to carcinogens.

Explore this trend in other countries

Every second, 10 cows, 47 pigs, and 2,400 chickens are slaughtered for meat

Chart showing the average number of cows, pigs, and chickens slaughtered for meat worldwide per second in 2022. It's 10 cows, 47 pigs, and 2400 chickens per second.

Around the world, 10 cows, 47 pigs, and 2,400 chickens get killed for meat every second.

Recent estimates suggest that 99% of livestock in the United States is factory-farmed. Globally, the majority of animals are raised on factory farms.

For many of these animals, life is short and painful.

Newborn calves are typically taken from their mothers shortly after birth, causing distress for both. Castrating and cutting off piglets' tails without anesthesia is common practice. Chickens grow so quickly that after six weeks, many struggle to stand for long and spend most of their time lying down. These animals require high doses of antibiotics to survive in poor living conditions.

There are ways to make life less harsh for farm animals. Reducing meat consumption can lessen the demand for factory farming and its associated harms. Moreover, slowing chicken growth rates or giving hens better living spaces can help reduce their suffering.

These figures are based on estimates from the Food and Agriculture Organization of the United Nations.

Explore many more charts in our Animal Welfare Explorer

Which type of cancer kills the most men in each country?

Cancer is one of the most common causes of death worldwide. In several countries, it is the most common cause of death.
But which cancers cause the most deaths?
This map shows the data for men. It presents the most common type of cancer death, based on the cause listed on death certificates, compiled by the WHO Mortality Database. Many countries are not shown as they lack sufficient death registration.
Lung cancer is the most common in many countries. In several others, especially in South America, prostate cancer leads.
In Iran, stomach cancer, and in Mongolia and Egypt, liver cancer, are the most common. 
Many of these cancers are preventable. Stomach cancer, for example, has declined almost ten-fold in the last seventy years in the United States thanks to improvements in food safety, hygiene, and antibiotics. Meanwhile, lung cancer death rates have halved since their peak with the fall of smoking.

Cancer is one of the most common causes of death worldwide. In several countries, it is the most common cause of death.

But which cancer types cause the most deaths?

The map presents the most common type of cancer death among men. This is based on the cause listed on death certificates, compiled by the WHO Mortality Database. Unfortunately, many countries are not shown as they lack sufficient death registration.

Lung cancer is the leading cause of male cancer deaths in many countries, primarily driven by smoking.

In parts of Latin America, prostate cancer leads. Although it has high survival rates in richer countries, it is common and can reach late stages before diagnosis, which limits treatment options.

Stomach cancer — shown in purple on the map — is the leading cause in several Central Asian countries. It is primarily caused by H. pylori infections. In wealthier countries, infections have declined thanks to better food safety, hygiene, and antibiotics.

Liver cancer, leading in Mongolia, Thailand, and Egypt, is often the result of inflammation caused by long-term alcohol consumption or hepatitis virus infection.

Learn more about the rates of different cancers and how they have changed over time

Nearly half of teenagers globally cannot read with comprehension

Nearly half of teenagers globally cannot read with comprehension

The chart shows the share of children at the end of lower-secondary school age — aged 12 to 15 — who meet the minimum proficiency set by UNESCO in reading comprehension. This means they can connect the main ideas across various texts, understand the author’s intentions, and draw reasoned conclusions.

Only around half of children of this age can read this well. In countries like Ireland and South Korea, more than 8 in 10 children reach this level. But in poorer countries like Senegal, Zambia, and Cambodia, fewer than 1 in 20 do.

These numbers include all children of middle school age, not just those who attend school.

Explore the most recent education data from UNESCO, now available in our updated charts →

Per capita CO2 emissions have peaked globally, but total emissions are still increasing

A line chart showing global per capita CO2 emissions from 1850 to 2023. The red line represents emissions from fossil fuels, peaking in 2012 at about 4.9 tons per person. The green line shows combined emissions from fossil fuels and land use, peaking slightly earlier. Both lines show a sharp rise starting in the 20th century and recent declines. The source is the Global Carbon Budget (2024).

To tackle climate change, the world needs to rapidly reduce global greenhouse gas emissions. But before we reduce emissions, we need to stop them rising; the world needs to pass the peak.

Globally, total CO2 emissions are still slowly increasing. The Global Carbon Project just released its preliminary estimates for 2024, which suggest another 0.8% increase.

However, while total emissions have not yet peaked, emissions per person have. Globally, per capita CO2 emissions from fossil fuels peaked in 2012. When land use emissions — which are more uncertain and noisier — are included, they peaked in the 1970s and have fluctuated since then. You can see both trends in the chart.

This suggests that, globally, lifestyles are slowly decarbonizing. However, to come closer to our global climate targets, economies must decarbonize much faster to push total emissions into decline.

Explore the latest CO2 emissions data in our updated charts →

Measles vaccines have saved over 90 million lives in the last 50 years

The image shows a bar chart titled "Number of lives saved by childhood vaccinations from 1974 to 2024," sourced from Shattock et al. (2024). A total of 93.71 million lives have been saved by measles vaccines since 1974. Other diseases include tetanus (27.95 million) and whooping cough (13.17 million). The data highlights the large impact of vaccination programs globally.

Measles vaccination has saved 94 million lives globally since 1974. Of those, 92 million were children.

The chart shows the number of lives saved by different childhood vaccines in the last 50 years. These estimates come from Andrew Shattock and colleagues and are based on global data on diseases, causes of death, vaccination rates, and vaccine efficacy.

Measles vaccines rank the highest in the total number of lives saved.

Measles is especially contagious and deadly. The virus depletes immune cells, making it harder to fight off measles and making other infections much more life-threatening. It can also erase immune memory to infections and vaccines that children have already encountered.

Before vaccines, almost all children caught measles, and it was a common cause of disability and death. With high measles vaccination rates, millions of lives are saved globally each year.

Read more in our article about the impact of global vaccination

The UN projects that Africa’s population will double by 2070

Today, Africa is home to 1.5 billion people. By 2070, the UN expects this number to more than double. Its estimates range from 2.7 billion to 3.7 billion, with the most likely scenario placing the African population around 3.2 billion.

This region is where most of the growth in the world population will occur in the next 50 years.

Europe’s population is already shrinking, with Asia and Latin America expected to follow from the 2050s onwards. The UN expects North America’s population to grow, although much slower than Africa's.

Read more about population growth →

In these nine African countries, average incomes have more than doubled since 1990

Economic growth is most important for the world's poorest people, and most of the world’s poorest live on the African continent. Are Africa’s economies growing?

The picture is mixed. In some countries, incomes have unfortunately declined in the last decades. This includes Madagascar, Zimbabwe, and Burundi. I have written about this in my brief explainer on extreme poverty.

In today’s Daily Data Insight, I want to focus on the other side: I want to highlight the African countries that are achieving economic growth. Nine of them are shown in the chart above.

In all nine countries, people’s average incomes have more than doubled since 1990.

This made substantial improvements in living standards possible: the share of people in extreme poverty and the rate of child mortality declined in all nine countries.

If you want to know more about the importance of growth and how it can be measured, you could read my article: What is economic growth? And why is it so important?

In 2023, PEPFAR provided life-saving therapy against HIV to 20.5 million people

Line chart titled '20.5 million people receive antiretroviral therapy through PEPFAR' showing the annual number of people receiving antiretroviral therapy through PEPFAR, the US President’s Emergency Plan for AIDS Relief, from 2004 to 2023. The chart starts near zero in 2004, rising steadily each year, and reaching 20.5 million people in 2023. The therapy helps keep people with HIV healthy and prevents its spread to others. Data source: President's Emergency Plan for AIDS Relief (2024), published by Our World in Data.

The US President’s Emergency Plan for AIDS Relief, known as PEPFAR, was established in 2003 to fight the global HIV epidemic.

Since its launch, PEPFAR has provided millions of people with antiretroviral therapy (ART) worldwide, especially in Africa.

The chart shows the number of people who received therapy through PEPFAR in a given year. In 2023, it was 20.5 million people.

ART is highly effective: it helps keep people with HIV healthy and reduces the risk of spreading the virus to others, saving more than one million lives each year.

But, after months of legislative delay, PEPFAR was recently renewed for only one year, raising concerns about the program's future after March 2025.

Explore data on other aid success stories →

Spotting and fixing data issues: how we help improve data quality on and off our publication

Line chart showing an example of a data error that was detected and flagged for correction. The old data has a large spike in the middle of the timeline, while the new data shows a consistent line without the anomaly.

In today’s Data Insight, we’re sharing a behind-the-scenes look at a part of our work we rarely talk about, but that is crucial in contributing to a more accurate understanding of the world.

We work with hundreds of datasets from many different sources. To check their quality, we’ve built in-house tools that flag unusual patterns, helping us spot when something seems off. Even in high-quality datasets, occasional errors can slip through.

The chart shows a recent example: after we updated a dataset, we noticed an unexpected spike in one of its time series. Investigating further, we traced the issue back to the data provider and let them know. They reviewed it, confirmed the problem, and corrected the error. Thanks to exchanges like this, several datasets have been improved this year.

Improving data quality is always a collaborative effort. We deeply appreciate the work of statisticians and data providers worldwide, who play a critical role in creating and maintaining these datasets. Our role is to help flag issues when we spot them and provide constructive feedback to make the data better for everyone.

The world population grew fast over the last 60 years, but farmers grew fruits and vegetables even faster

For almost all of human history, food was scarce for nearly everyone. The reason for this perpetual scarcity was that whenever food production increased, it did not lead to more food per capita but to more people.

Food production did not increase per capita. Population pressure ensured that living standards remained only barely above the subsistence level. Economic historians refer to this mechanism as the Malthusian Trap, and if you’d like to know more, you could read my article about it.

This changed in the last decades. More and more societies around the world broke out of the Malthusian Trap. We see this in the data as increasing food production in per capita terms. The chart shows that farmers have grown many fruits, vegetables, and nuts faster than the world population has increased.

The increase in global agricultural output was crucial for the reduction of hunger and famines that the world achieved in this period. Whether or not we will be able to end hunger globally will depend on whether this increase in food production will continue.

Explore global and country-specific data on a wide range of foods in our Food Data Explorer →

Fossil fuels are the biggest source of CO2 emissions in most countries, but there are a few exceptions

Six area charts display the share of CO₂ emissions from fossil fuels versus land-use change across the world, United States, United Kingdom, China, Brazil, and Indonesia. Fossil fuel emissions dominate globally, particularly in the U.S., U.K., and China, where over 90% of emissions come from fossil fuels and industry. However, in Brazil and Indonesia, a significant portion of emissions arises from land-use change, especially in Brazil, where it is the main source.

Around 90% of the world’s carbon dioxide (CO2) emissions come from fossil fuels and industrial processes such as cement production. The other 10% comes from land use change, primarily carbon released from trees and vegetation due to deforestation.

Fossil fuels are also the biggest source of emissions at the national level in most countries across the world. But there are a few exceptions.

In the chart, you can see the share of emissions from fossil fuels compared to land use change across a small selection of countries. In the United States, the United Kingdom, and China, fossil fuels dominate. This data comes from the Global Carbon Project.

However, in Brazil, land use change plays a much more significant role. This is for two reasons. First, deforestation rates are higher than in most other countries. Second, Brazil has a very clean power grid. Most of its electricity comes from hydropower, with solar and wind also growing quickly. It burns very little coal and gas.

Explore data on how emissions compare across the world and by source →

The United States is the world’s largest oil producer

Line chart showing oil production by country since 1990. The United States is now the world's largest producer and has been for the past seven years.

The United States is the world’s largest oil producer.

The chart shows annual production by country from 1990 to 2023. The US has been the largest producer for the last seven years.

Production in the US gradually declined during the 1990s and early 2000s but increased steeply again post-2010 and is now at an all-time high.

This data comes from the Energy Institute’s Statistical Review of World Energy.

Explore oil production data for more countries and further back in time →

Spain and Portugal both get 40% of their electricity from solar and wind

Line chart showing the share of electricity produced from solar and wind in Spain and Portugal. Both countries got around 40% from these sources in 2023.

European neighbors Portugal and Spain are currently neck-and-neck in the race to roll out solar and wind power.

On the chart, you can see the share of electricity from the combination of solar and wind in each country. Their rate of progress has been very similar.

In 2023, both countries generated around 40% of their electricity from these sources. Wind power is more prevalent in Portugal, while solar is more used in Spain.

This data comes from Ember.

Explore more data on the rollout of clean energy across the world →

Global mean sea levels have increased by around 25 centimeters since 1880

Line chart showing global mean sea level rise since 1880. It has increased by around 25 centimeters.

There are two key drivers of sea level rise. First, water expands as it gets warmer. Second, ice on land — in the form of ice sheets and glaciers — melts and adds water to ocean basins.

Both of these processes have accelerated due to climate change. The effect is shown in the chart, based on data from the US’s National Oceanic and Atmospheric Administration. It combines two sources: recent data from the University of Hawaii Sea Level Center and a publication from Church and White (2011).

On this chart, the rise in sea level is measured relative to the average from 1993 to 2008. Levels had risen by almost 20 centimeters between 1880 and this period, and 5 more centimeters since. Combined, that’s around 25 centimeters.

Explore more data on the impacts of climate change →

Most carbon emissions from food miles are produced by trucks on the road

Bar chart showing where carbon emissions from food miles come from. Road transport is 3.9% of food system emissions, compared to just 0.02% from aviation.

Food miles — moving products from farms to processors to consumers — contribute just 5% to 6% of the greenhouse gas emissions from food. Instead, most emissions come from land use change or emissions on the farm.

Within food miles, people often assume that international freight accounts for most of the climate impact. In reality, most of these emissions come from domestic delivery trucks on the road.

In the chart, you can see the breakdown of transport’s 5% of food emissions. Road transport represents 3.9%, compared to just 0.02% from aviation. This is based on data from a 2021 study by researchers M. Crippa and colleagues.

International food miles are just a small share of emissions because very little food is flown by air, and transporting goods by boat is much more carbon-efficient than by road.

Read more about the impact of food miles →

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