Infant mortality rates have plummeted over the last 50 years. Globally, they’ve fallen by over two-thirds, from around 10% in 1974 to less than 3% today.

A recent study — published in The Lancet by Andrew Shattock and an international team of researchers — estimates that increased access to crucial vaccines means that infant mortality rates are 40% lower than they would be in a world without vaccines.

The chart shows the actual reduction in infant mortality rates with vaccination (in blue) and the researchers’ estimates for a hypothetical scenario in which vaccines wouldn’t have been rolled out (in red).

Based on these figures, vaccines are estimated to have saved 150 million children over the last 50 years. Vaccinations accounted for 40% of that decline.

Read our article on the role of vaccination in reducing infant mortality →

The chart shows that the average worker in wealthy countries now works only about half as many hours per year as in the late 19th century.

Based on data from economic historians Michael Huberman and Chris Minns, the average worker used to work between 2,700 and 3,500 hours per year, which is about 50 to 70 hours each week.

Recently, using data from the Penn World Table, workers worked about half that amount, between 1,300 and 1,800 hours a year, or about 25 to 35 hours a week.

This decrease has come from working fewer hours each day, fewer days each week, and fewer weeks each year.

Read more in our article on whether we are working more than ever →

Four decades ago, when HIV was first identified, it was an invariably fatal disease: nearly 100% of those infected died, typically within a few years.

The virus spread rapidly around the world — especially in Africa, where almost two million were dying every year by the millennium.

Thankfully, medical advances and global public health efforts have entirely changed this course. Modern antiretroviral therapy is very effective in both treating HIV — returning people with HIV to near-normal life expectancy — and preventing the virus from spreading to others.

The chart above shows this impact based on data from UNAIDS. Over a million people's lives are now saved by antiretroviral therapy each year.

Recent medical advances could take this progress even further.

Read more on how antiretroviral therapy has changed the lives of people with HIV →

Cereals, roots, and tuber crops — such as cassava or potatoes — are some of the cheapest options for getting enough calories. In poorer countries, people get much of their daily energy from these crops.

The chart shows the share of calories that the average person gets from these staples, measured against gross domestic product (GDP) per capita. This data comes from the Food and Agriculture Organization of the United Nations and the World Bank.

People in some of the world’s poorest countries get two-thirds to three-quarters of their calories from cereals and other staples, compared to around one-third in the richest countries.

This means those on low incomes have less diverse diets and often miss out on key nutrients from legumes, fruit and vegetables, meat and dairy, and other foods.

Explore the data →

Generative AI is a type of artificial intelligence that can create various media, including text, images, and music. It learns from existing data to generate novel outputs. Examples include language models like GPT-4 and Claude, which can write essays or answer questions, and image generation models like Midjourney and DALL·E, which can create artwork based on textual descriptions.

In 2023, funding for generative AI soared to $22.4 billion, nearly nine times more than in 2022 and about 25 times the amount from 2019. This surge occurred despite overall investment in AI declining since its 2021 peak.

The data is produced by Quid and made available through the AI Index Report. Quid analyzes investment data from over 8 million companies, using natural language processing to uncover patterns and insights from vast datasets. We have recently updated our charts on Our World in Data with the report's latest edition.

Read more on how investment in AI has been changing over time here →

This chart shows the gender breakdown of people affected by homelessness.

In most countries, men tend to be more likely to experience homelessness than women. In many, women make up 20% to 40% of the homeless population.

But this ratio varies a lot by country. In Colombia and Costa Rica, men are much more likely to be affected by homelessness, with only around one in ten being women.

In the United Kingdom and New Zealand, it’s even the opposite: more women experience homelessness than men.

This data comes from the OECD’s Affordable Housing Database and only includes countries that count people experiencing homelessness on a single night of the year.

Explore our updated and expanded topic page on homelessness →

Over the 1980s and 1990s, the rise in HIV/AIDS deaths seemed unstoppable. Several effective antiretroviral drugs had been developed, but people with HIV still died from the disease because the virus would evolve to evade each drug.

Thankfully, scientists discovered that a combination of drugs could create a significant barrier to HIV’s evolution. This new treatment, highly active antiretroviral therapy (HAART), was first introduced in 1995 in the United States.

Data from the National Center for Health Statistics shows the massive impact of HAART in the chart. HIV/AIDS mortality dropped steeply after it was introduced.

It profoundly improved the survival of people with HIV and reduced their risk of passing it on to others.

Read more about the impact of antiretroviral therapy →

Exoplanets are planets that orbit stars other than the Sun. Their existence was first confirmed in 1992 when astronomers Aleksander Wolszczan and Dale Frail identified two exoplanets orbiting a star located 2,300 light-years from Earth.

As shown in this chart, from 1992 to 2005, scientists discovered two hundred more exoplanets. They primarily used a method called "radial velocity". This technique works by detecting small changes in the color of a star due to the gravitational pull of a planet orbiting it.

But starting in the mid-2000s, the "transit method” vastly accelerated the pace of exoplanet discovery. This method detects tiny dips in a star’s brightness when a planet passes in front of it. This dimming can reveal a planet's presence and provide information about its size and orbit.

As is often the case with technological change, what was once a unique scientific achievement has become a much more frequent occurrence. The advancements in detection methods now allow us to discover hundreds of exoplanets each year.

Adding up all methods of identification, more than 5,500 exoplanets have been found by scientists worldwide, according to data from NASA's Exoplanet Archive.

Browse more charts on astronomy and space exploration →

Richer people tend to have more diverse diets. They get a lower share of their calories from staples such as cereals, roots, and tubers and increase their consumption of fruit, vegetables, dairy, and meat.

The chart shows the relationship between meat supply and gross domestic product (GDP) per person. Meat supply — as reported by the Food and Agriculture Organization of the United Nations — measures the average quantity of meat available for consumers. It includes how much people ultimately eat and any consumer waste.

There is a strong positive relationship: people in wealthier countries tend to eat more meat per person. This has also meant that as the world has gotten richer, global meat production has increased.

Explore the data →

This chart shows the share of reported deaths caused by cardiovascular diseases and cancer since 1950 in Denmark, Australia, the UK, and Canada. This is based on the underlying cause listed on death certificates and comes from the WHO Mortality Database (2024); we recently updated our charts with the latest release.

Fifty years ago, around half of all deaths in these countries were due to cardiovascular diseases. Today, this proportion has dropped to between 20% and 25%. Cancer has become the most common cause of death in many of these countries, even though overall cancer mortality rates have also been declining.

Many factors contribute to these trends, such as declines in smoking and improvements in screening, diagnosis, and monitoring.

These countries are also leading the use of statins, medicines that lower cholesterol, which likely have had a significant effect on reducing heart-related deaths.

Even though fewer people are dying from cardiovascular diseases in some of these wealthy countries, heart disease remains the leading cause of death worldwide.

Read more on the different types of cardiovascular diseases →

Recent data from Global Forest Watch shows trends in tree cover loss, split by five drivers: forestry, shifting agriculture, and wildfires, which lead to temporary tree cover loss, while commodity-driven deforestation and urbanization often cause permanent deforestation.

This dataset combines time-series data of tree cover loss, estimated from satellite imagery using research by Matthew Hansen and colleagues, with research on the drivers of deforestation by Philip Curtis and colleagues.

The drivers of tree cover loss vary markedly across regions. Wildfires and forestry (logging) are the main drivers of tree cover loss in Europe and North America, with wildfires mainly occurring in Canada and Russia. Tree cover loss from wildfires does not include fire clearing for agriculture.

Commodity-driven deforestation is a key cause in Asia and South America, largely due to trends in Brazil and Indonesia. Shifting agriculture — where trees are cleared so the land can be cultivated temporarily before being abandoned — is the dominant driver of tree cover loss in Africa and a major driver in South America.

Explore the drivers of tree cover loss for all countries and regions →

Countries have very different rates of homelessness, according to the OECD’s Affordable Housing Database.

The chart shows that more than 300 out of every 100,000 are reported homeless in France, while it’s fewer than 20 in Finland.

In about half of the countries, more than 100 in every 100,000 people are homeless. That means more than one per thousand people.

There are also differences in types of homelessness. The United States, for example, has relatively high numbers of people living in the streets or public spaces but fewer in temporary accommodations or shelters.

Not all countries on the chart can be directly compared. For example, Japan and Greece only report data on one type of homelessness, so they don’t give a complete picture of the total population affected by homelessness.

Explore our updated and expanded topic page on homelessness →

The chart shows the weekly area burned by wildfires globally and in Africa from 2012 to 2024. This August saw an abrupt increase in the area burned by wildfires, with most of this rise coming in a single week.

This global weekly burn rate was 64% higher than any previous week during this period. This data comes from the Global Wildfire Information System.

This dramatic rise was mostly driven by severe wildfires in Africa, where approximately 22 million hectares burned in a week, accounting for around 80% of the global burned area.

Two countries have been particularly hard-hit — Angola and the Democratic Republic of Congo — where 6% and 2.5% of the total land area have burned in just one week.

Explore wildfire data across the world, updated weekly →

Smallpox was a deadly disease that has been recorded since ancient times. It killed around 30% of those who developed the disease.

In 1980, it became the first disease to be eradicated worldwide. This considerable achievement resulted from centuries of coordinated effort and scientific development.

People were able to fight the virus by developing and refining smallpox vaccines, using quarantine control measures, and applying ring vaccination.

Many countries — in Europe, the former Soviet Union, and many island nations — eliminated smallpox around a century ago. This is shown on the map, whose data was compiled by researchers Frank Fenner and colleagues in 1988.

Smallpox continued to kill in many countries in South Asia, Africa, and South America until the 1970s. It remains a vivid memory for many older people alive today.

Read more about the history of smallpox and its eradication →

The United Kingdom was the birthplace of coal. It has now, effectively, died there.

As shown in the chart, in the late 1980s, around two-thirds of the UK’s electricity came from coal. By the time I was born in the 1990s, this had dropped to just over half.

The use of coal has plummeted in my lifetime. It now makes up less than 2% of the UK’s electricity.

Coal was first replaced by gas but is now being pushed out by wind, solar, and biomass.

Read more about the death of UK coal →

Around the world, women tend to live longer than men.

However, the sex gap in life expectancy has changed over time, as this chart shows. The data comes from combining the WHO’s Human Mortality Database and the United Nations World Population Prospects.

As you can see, the sex gap in life expectancy — defined as female life expectancy minus male life expectancy — was around 3 years in the 19th century in countries like France and Sweden. It spiked during the two World Wars, as deaths surged among young men in combat.

But it also grew gradually over the 20th century to around 7 years.

One reason for this widening gap was the rise in tobacco smoking, especially among men. Smoking increases the risk of various cancers and heart disease and leads to premature death.

Since then, as smoking has declined, the sex gap in life expectancy has narrowed in many countries.

Read more about why women tend to live longer than men →

The number of countries that possess nuclear weapons has never been higher. Only one country that had them — South Africa — entirely dismantled its arsenal.

But, as the chart shows, many more states had considered or pursued nuclear weapons in the past — they are displayed in yellow and orange.

In the late 1970s, more than a dozen countries considered them or pursued them by launching nuclear weapons programs, but almost all stopped. Only Syria has considered nuclear weapons recently, and only Iran has pursued building them.

This data is based on the work of political scientist Philipp Bleek and the Nuclear Threat Initiative.

Find out which countries gave up obtaining nuclear weapons →

Improved crop yields have allowed us to feed billions more people while sparing forests and other land from agriculture.

Global cereal yields have tripled since 1961. And as you can see in the chart, they have increased in all regions.

However, yields across most African countries have lagged behind. At 1.7 tonnes per hectare, they’re still less than half the global average of 4.2 tonnes.

This is bad for farmers: they get much smaller harvests and live on much lower incomes. It makes it harder for countries to feed their populations. And it’s a problem for biodiversity: lower yields mean that farmland has to expand into wild habitats.

Increasing agricultural productivity — particularly across Africa — is one of the biggest challenges of this century.

Explore the data →

The world has made progress against the tragedy of infant mortality. But infants remain at risk, especially after birth.

The experience of a baby leaving the womb and entering the world is a sudden change, and birth complications, suffocation, trauma, and sepsis can be fatal.

The chart shows the risks over the first year of life. It uses national data from the United States Centers for Disease Control and Prevention to show the daily death rate (on the vertical axis), plotted against the baby’s age in days (on the horizontal axis).

As you can see, the first day of life is the riskiest. Risks then decline sharply in the days following birth and continue to decline gradually over the rest of the year. This pattern is seen across countries.

Read more about how mortality risks change over our lifetimes →

Data from the World Bank shows that paid leave for early childcare varies a lot around the world.

The chart shows several key differences. In some countries, like India, only mothers get paid leave. In France, fathers also get paid leave. Parents in Russia can partially share the leave.

There are also differences in the purpose of the leave. In countries like South Africa, it’s for childbirth. In others, like the United States, it’s for childcare in the months after birth. In countries like China, paid leave covers both childbirth and early childcare.

The length of paid leave differs immensely, too. In Egypt, for example, only 90 days are available, while in Japan, parents have a combined total of 800 days.

What’s not shown in the chart is how much money parents receive. This also varies a lot between countries.

These differences in government support affect young families’ finances, how childcare is shared, and how much time newborns spend with their parents.

Explore this data over time and for more countries →