Daily Data Insights

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

In the last 200 years, many countries have built institutions to collect statistics on their populations

Line chart showing that many countries have established censuses, civil registers, population registers, and statistical agencies that collect basic statistics about their people over the last centuries.

Governments need accurate information about their populations to implement effective policies.

But historically, few countries collected basic statistics on their people, so they knew little about them.

The chart here shows that, over time, many countries have built such institutions.

Starting in the 19th century, they began conducting population censuses, creating civil registers, and establishing statistical agencies. In the later 20th century, they started setting up population registers and using register-based censuses.

Thanks to these efforts, these countries better understand where people live, what jobs they have, who was born, and who has died.

However, many countries still lack these institutions, which makes it challenging for them to direct projects and policies where they are most helpful.

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More than 30 countries have legalized same-sex marriage

Line chart showing the number of countries where same-sex marriage is legal.

The Netherlands was the first country to legalize same-sex marriage in 2001. Since then, more than 30 other countries have followed suit.

You can see this in the chart, based on data from Pew Research. By 2022, same-sex marriage was legal in 32 countries.

Since then, 3 more countries have joined this group: Andorra, Estonia, and Greece — bringing the total to 35. Last year, Nepal also registered its first same-sex wedding, but it’s not yet clear whether these rights are available across the country.

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Global population growth peaked six decades ago

A chart displays the global population growth rate from 1950 to 2100, highlighting a peak in the 1960s and a projected decline into negative growth by the end of the century. The data is based on UN projections with a medium-fertility scenario.

The increase in the world’s population is not exponential. The global population is growing, but the growth rate has declined since its peak six decades ago.

The chart shows the annual rate of global population growth according to historical estimates and projections from the UN World Population Prospects.

The growth rate peaked in 1963 at over 2% per year, and since then, it has more than halved, falling to less than 1% by 2020.

The UN demographers expect rates to continue falling until the end of the century, eventually leading to negative growth rates and a shrinking global population.

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Drug-resistant tuberculosis is much more expensive to treat

Tuberculosis is usually treatable with a specific combination of antibiotics.

But without proper treatment, the bacteria can survive and potentially develop antibiotic resistance to more and more drugs.

This drug-resistant bacteria can then spread to others, causing disease that’s much more difficult and expensive to treat.

The chart shows the cost of treating a single patient with tuberculosis, depending on their type of tuberculosis.

For tuberculosis patients in India without drug-resistance, the average cost of treatment is only $24.

But among patients who have multi-drug resistant tuberculosis, the cost is almost $400. With extensively drug-resistant tuberculosis, it’s more than $1000.

Tuberculosis is usually treatable with a specific combination of antibiotics. However, without proper treatment, the bacteria can survive and develop antibiotic resistance to an increasing number of drugs. This drug-resistant bacteria can then spread to other people, making the disease much more expensive to treat.

The chart shows the cost of treating a single patient with tuberculosis in India.

For tuberculosis patients without drug resistance, the average cost of treatment is only $24.

But among patients who have multi-drug resistant tuberculosis, the cost is almost $400. With extensively drug-resistant tuberculosis, it costs more than $1,000. That’s about 50 times higher than patients without drug resistance.

The share of democracies has recently stagnated but remains near its historical high

Stacked area chart of the share of countries that are democracies and autocracies between 1973 and 2023. The share of closed autocracies decreases a lot over time, but recently increases. The share of liberal democracies decreases slightly over time, but recently decreases. The share of electoral democracies increases a lot and recently stagnates. The share of electoral autocracies increases over time.

Over the last twenty years, the share of countries that are democracies has remained relatively stable.

Relying on data from Varieties of Democracy, which we just updated, the chart shows that around half of all countries are democracies.

The world remains close to the historical high in the early 2000s and is much more democratic than 50 years ago; only 20% of countries were democracies in the early 1970s.

However, the chart shows smaller changes within democratic regimes: the share of liberal democracies, which grant additional individual and minority rights and constrain their governments, has decreased over the last decade.

While democracy has remained fairly resilient over the last few decades, this recent stagnation and limited rollback stresses that progress on increasing political rights is neither linear nor guaranteed.

Read more about the recent changes in democracy

Commercial flights have become significantly safer in recent decades

Line graph showing the rate of fatal airliner accidents per million commercial flights globally from 1970 to 2020. The graph depicts a general declining trend over the 50-year period. It starts with fluctuations around 5 to 6 accidents per million flights in the early 1970s, followed by a variable but overall downward trend leading to less than 2 accidents per million flights by 2020. This indicates an improvement in aviation safety over time. Data sources include the Aviation Safety Network (ASN) and the World Bank's World Development Indicators. The chart is provided by OurWorldInData.org/tourism and is licensed under CC BY

According to figures from the Aviation Safety Network, in the 1970s, there were about 6 fatal airliner accidents for every million commercial flights. This meant about 1 in every 165,000 flights ended in a fatal accident.

As the chart shows, this figure has dropped steadily in the last 50 years. According to the latest data, it is now about half a fatality per million flights. This means that, on average, it now takes more than 2 million flights for a fatal accident to occur.

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Sulfur dioxide emissions from shipping dropped sharply with the introduction of new rules in 2020

Line chart showing global emissions of sulphur dioxide by sector.

The Community Emissions Data System (CEDS) produces invaluable long-term data on the emissions of air pollutants worldwide. It has just published its latest update, extending this data to 2022.

One of the most striking changes in air pollution trends has been the abrupt drop in sulfur dioxide (SO2) emissions from shipping. As you can see in the chart — where shipping is highlighted in red — there was a dramatic fall from over 10 million tonnes a year in 2019 to 3 million tonnes a year later.

The change resulted from the International Maritime Organization’s strict limits on marine fuels, introduced in 2020: the maximum percentage of sulfur allowed in these fuels fell from 3.5% to 0.5%. All ships worldwide had to comply.

This drop is positive for tackling local air pollution and acid rain. However, it also has implications for climate change since SO2 has masked some of the warming caused by greenhouse gases.

Explore all of the updated data

Testing rates for polio have rebounded after a drop amid the COVID-19 pandemic

This chart, titled "Share of potential polio cases tested and reported to the WHO," shows how many suspected polio cases were actually tested for the virus and reported to the World Health Organization from 2001 to 2023. The graph tracks this data for several countries, including Nigeria, Afghanistan, Malawi, Pakistan, Indonesia, Mozambique, and Botswana. Ideally, at least 80% of suspected cases should be tested to ensure none are missed, as recommended by the WHO. The lines on the graph fluctuations for each country over the years, with a noticeable dip around 2020 during the global COVID-19 pandemic. However, the graph also shows a rebound in more recent years, indicating that testing for polio has picked back up again. This is important for keeping up the fight against polio and moving towards its eradication.

The world is close to eradicating polio. Annual cases have dropped from an estimated 400,000 in the 1980s to less than 4,000 in recent years.

But, to cross the finish line, sufficient testing is crucial to ensure that cases aren’t missed.

The World Health Organization recommends that at least 80% of potential polio cases be tested for the virus. Potential cases are identified based on “acute flaccid paralysis”, a sudden onset of paralysis in the limbs.

As shown in the chart, disruptions from the COVID-19 pandemic led to a drop in polio testing rates in many countries. Thankfully, this new data shows that polio testing has rebounded.

This is due to the dedicated effort of countless health workers and opens the way to a future free from polio.

30% of the world's electricity came from renewable sources in 2023

Line chart showing the share of global electricity that comes from renewables.

Renewable electricity production is growing quickly, mostly thanks to the deployment of solar and wind.

Ember has just published its latest Global Electricity Review, which includes final updates on electricity generation worldwide in 2023. We have updated our Energy Data Explorer with all of this data.

As the chart shows, renewables produced just over 30% of the world’s electricity in 2023.

This growth was mostly driven by the rapid rollout of solar and wind technologies. Hydropower generation actually fell in 2023 as a result of severe droughts, especially in China.

Explore the updated data from Ember

The rise of tax revenues in Southern Europe

Line chart showing that the Southern European countries Greece, Spain, and Portugal have increased their tax revenues over the past decades, and while they were previously closer to the United States, now are close to Germany.

Southern Europe demonstrates that countries can substantially increase the taxes they collect in a relatively brief period of time.

The chart shows that in 1980, tax revenues in Greece, Portugal, and Spain accounted for around 20% of their respective GDP, based on data from UNU-WIDER. This was slightly less than the United States’s 25% of GDP and much lower than Germany’s 36%.

Within a few decades, the three countries greatly increased their tax revenues. By 2021, they had almost caught up with Germany, with revenues nearly 40% of GDP. Even the 2007–2008 economic crisis only briefly interrupted their upward trend.

This shows that governments can increase their tax collection to expand public policies, even in countries where taxes were comparatively low in the past.

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The age structure of populations varies widely across countries


The image is a world map titled "Age group with the largest population, 2021," showing the ten-year age group that has the largest population in each country. The map uses a color-coded system to differentiate age groups: yellow for ages 0-9, light green for ages 10-19, teal for ages 20-29, light blue for ages 30-39, blue for ages 40-49, dark blue for ages 50-59, and dark teal for ages 60-69. Most European countries have older populations. North America predominantly has the largest population in the 30-39 age group, while much of Africa shows the largest population in the 0-9 age group. The source of the data is the United Nations - World Population Prospects (2022) and the image is credited to Our World in Data.

There are many ways to examine a country's age structure. One interesting approach is to look at the age group with the largest population, as shown in the world map.

Across most African countries, the largest demographic is children younger than 10.

This contrasts sharply with Europe, where the largest age groups tend to be much older. Many European countries are most heavily populated by those in their 30s, 40s, and 50s. For example, the fifties are the largest age group in the United Kingdom and the Netherlands. In Monaco and Croatia, the most populous are those in their sixties.

If we look back to 1950, the map looks very different. Small children and teenagers were the most populous age groups in almost all countries.

Over the last 70 years, birth rates have declined in most countries, and life expectancy has increased, leading to aging populations worldwide.

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Was the global decline of extreme poverty only due to China?

Line chart showing the decrease in the share in extreme poverty for both the world and the world without considering China

The share of the world population living in extreme poverty has never declined as rapidly as in the past three decades.

The decline in China was particularly fast, and given that one in six people in the world live there, we’re often asked whether the decline in global poverty was only due to the decline in China.

The chart shows the data that answers this question. In red, we see the global decline. In green, we see the decline if we exclude China from the data. In the world outside of China, 29% lived in extreme poverty in 1990 — by 2022, this share was down to 11%.

The large economic growth that lifted 800 million Chinese people out of extreme poverty since 1990 was a major contributor to the global decline in poverty. But the non-Chinese world also achieved a very large reduction.

It is not true that the global decline in poverty was only due to China. Extreme poverty has declined in China and the rest of the world.

Data on suicides is lacking, especially from poorer countries

Line chart showing the fraction of countries with available data on deaths from suicide. The fraction is shown for countries of different income groups. Around 60% of high-income countries share data on annual suicide rates with the World Health Organization, but less than 20% of lower-middle-income countries do, and no low-income countries have done so since 2011.

Many countries do not collect or publish national data on suicides, especially poorer countries.

Around 60% of high-income countries have shared data on annual suicide rates in a given year with the World Health Organization, but less than 20% of lower-middle-income countries do, and no low-income countries have done so since 2011.

This lack of data is partly due to an absence of vital registries — where death certificates are collected — and coroners, doctors, and legal systems to determine and record causes of death across the population.

Without this data, statistical organizations estimate suicide rates based on other data, such as surveys and data from similar countries. This is challenging because suicide is highly stigmatized in many countries and sometimes even criminalized.

The chart also shows that more countries have improved their data collection and reporting systems. With more effort to improve vital registries, we will gain a greater understanding of where and why suicides occur, who is at risk, and how to prevent this tragic cause of death.

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The global eradication of polio is within reach

The image is a line graph titled "Reported cases of paralytic polio." It shows the annual reported cases of paralytic polio, including both cases from wild polioviruses and vaccine-derived polioviruses from 1980 to 2023. The line starts near 60,000 cases in 1980, sharply decreases to below 20,000 by the mid-1980s, and continues to decline steadily to just a few hundred cases by 2023. The x-axis represents the years, and the y-axis represents the number of cases. There are horizontal grid lines aiding in the reading of case numbers. At the bottom, the data source is credited to the World Health Organization (2019) and the Global Polio Eradication Initiative (2024). On the right side of the image is a logo with the text "Our World in Data." The website "OurWorldInData.org/polio" is listed along with a CC BY license notification.

Polio is a highly infectious viral disease that largely affects children, causing paralysis and permanent disability; it can also lead to death.

In the early 1980s, over 50,000 cases were reported annually. This only includes cases that have been diagnosed and reported to health authorities. The true number of total cases was likely higher than 300,000 in the worst years.

The number of reported cases has been dramatically reduced in recent years. We have just updated the data shown in the chart. Last year, there were 536 paralytic polio cases worldwide.

Much of this reduction has come from global efforts toward better vaccination and improved screening and testing, primarily coordinated by the Global Polio Eradication Initiative (GPEI), founded in 1988.

Global polio eradication is possible through high vaccination rates, thorough screening and testing to detect cases, and rapid, high-quality immunization campaigns to limit outbreaks.

Read more on how our generation can eradicate polio globally

Over 33,000 near-Earth asteroids have been detected since 1990

Graph titled 'Near-Earth asteroids discovered over time' from Our World in Data, showing the cumulative number of discovered asteroids with an orbit close to Earth from 1990 to 2023. The graph displays three layers: asteroids larger than 1 kilometer in dark purple at the bottom, those between 140 meters and 1 kilometer in purple in the middle, and smaller than 140 meters in orange at the top. The overall trend shows a significant increase over time. The data source is credited to the NASA Center for Near-Earth Object Studies (2024). A note clarifies that Near-Earth asteroids are defined as those whose closest approach to the Sun is less than 1.3 astronomical units (AU), with 1 AU being the distance from Earth to the Sun.

Since the late 20th century, astronomers and space agencies have taken steps to monitor the threat of large asteroids passing near Earth. International initiatives were established to detect, track, and characterize these celestial bodies to safeguard our planet from possible collisions.

As the chart shows, more than 33,000 near-Earth asteroids have been discovered and tracked since 1990. NASA estimates that over 90% of all the near-Earth objects larger than 1 kilometer have already been discovered.

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Emissions of substances that deplete the ozone layer have fallen by more than 99% since 1989

Graph titled 'Global emissions of ozone-depleting substances' showing the annual consumption of various ozone-depleting gases from 1986 to 2021, measured in ODP (ozone-depleting potential) tonnes. The stacked area graph indicates a peak around 1988 and a general decline thereafter. Each gas type is color-coded: CFCs, Halons, Carbon Tetrachloride, Methyl Chloroform, Methyl Bromide, and HCFCs. The data source is the UN Environment Programme (2023). A note explains that negative consumption values can occur when countries destroy or export gases that were produced in previous years, like stockpiles.

In 1987, countries around the world signed the Montreal Protocol to reduce emissions of ozone-depleting substances — such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and halon gases used in refrigerators, deodorants, and other industrial processes.

This chart shows that since the Montreal agreement entered into force in 1989, global emissions of ozone-depleting substances have fallen by more than 99% as manufacturers have substituted them for less harmful alternatives.

The Montreal Protocol is one of the most successful international agreements to date.

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Primary education in Morocco: from less than half to nearly universal attendance

Primary education in Morocco: From less than half to nearly universal attendance

In the 1970s, less than half of Morocco's primary-age children attended school. Today, nearly every child is in school, with enrolment rates having soared to over 99%, according to data published by UNESCO.

Though this is a remarkable achievement, there's still room for improvement in education quality. Only about a third of these students achieve basic reading comprehension by the end of primary school.

Focusing on getting children into school has been crucial. The next step is to enhance the quality of education to ensure they not only attend but also learn and thrive.

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Colombia’s homicide rate has more than halved since the 1990s

Line chart showing that Colombia's homicide rate has halved in recent decades, and is now much closer to the rates of the Americas and Europe (even though those are still much lower).

Half as many people died from homicides in Colombia in recent years than only a few decades ago.

In the 1990s, more than 60 people per 100,000 were killed in homicides each year, according to data from the United Nations Office on Drugs and Crime. Homicide was the cause of 15% of all deaths at the time.

The homicide rate has fallen significantly since then, as the chart shows. In 2021, it was around 27 homicides per 100,000 people.

The country’s rate is now much closer to the regional rate of the Americas, at 15 homicides per 100,000 people.

Still, this means that homicides are almost twice as common in Colombia than in its world region, and more than 13 times as common than in Europe — the safest world region — with only 2 homicides per 100,000 people.

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Nearly one in five cars sold in 2023 was electric

Bar chart showing the share of new cars sold in 2023 that were electric. Globally, this share was 18%.

The International Energy Agency (IEA) just published its latest annual Global EV Outlook. It provides its final estimates for sales of electric vehicles worldwide in 2023.

The IEA estimates that almost one in five (18%) cars sold in 2023 were electric — double the share from just two years earlier.

There are significant differences in adoption worldwide. This chart shows new sales shares by country. In Norway, more than 90% of new cars were electric. In China, it was almost 40%; in the European Union, 22%; and in the United States, just 10%.

These figures include fully electric vehicles and plug-in hybrids. You can find this data broken down by vehicle type in this chart.

Explore all of the updated data →

2023 was a population crossroad

Line chart showing the population trends for Africa, China, India

China is no longer the most populated country in the world. According to estimates by the UN World Population Prospects, India took over in 2023. That year, both countries had around 1.4 billion inhabitants — as many as the entire African continent.

However, as we can see in the chart, China’s population is expected to decline, and India’s growth is expected to slow down. Meanwhile, Africa’s population is expected to keep growing; the UN estimates it could reach close to 4 billion people by the end of the century.

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