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.

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 →

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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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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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.

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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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 →

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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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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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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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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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 →

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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Today, April 22, is Earth Day. This year’s theme is ending plastic pollution.

The world produces vast amounts of plastic: more than 450 million tonnes yearly. But when it comes to plastics leaking into our rivers and oceans, it’s the management of plastics — not their production or use — that matters most.

When plastic is not correctly recycled, incinerated, or stored in sealed landfills, it can pollute the environment. According to the OECD Global Plastics Outlook, around one-fifth of the world’s plastic waste is mismanaged in this way.

As this map shows, mismanaged plastic waste per person tends to be higher in low-to-middle-income countries. This is because their plastic use has increased much faster than their investments in waste management infrastructure. (These estimates come from research by Lourens Meijer and colleagues.)

To end plastic pollution, improvements in waste management — alongside more responsible use of plastics — will be critical. Domestic policies will be crucial, but richer countries can also contribute through foreign investments in waste management infrastructure.

Read more →

A woman dying when she is giving birth to her child is one of the greatest tragedies imaginable.

Every year, 300,000 women die from pregnancy-related causes.

Fortunately, the world has made continuous progress, and such tragic deaths have become much rarer, as the chart shows. The WHO has published data since 1985. Since then, the number of maternal deaths has halved.

Explore the data country by country →

China has significantly increased its number of nuclear warheads in the last 20 years.

In 2003, the country had 235 warheads. A steady increase brought this number to 280 in 2018, and a more recent acceleration to 410 as of 2023.

China now has a larger nuclear arsenal than France and the United Kingdom, as the chart shows.

It is not the only country expanding its arsenal: India and Pakistan have also increased the number of their warheads; and the global distribution of warheads remains dominated by Russia and the United States, which each have several thousand warheads.

But China has been the country most rapidly expanding its number of nuclear weapons in recent years.

This increases the risk of accidents and the threat nuclear weapons pose to humanity.

Read more about nuclear arsenals →

Global economic inequality is very large. We see this in the differences between average incomes across countries. In this chart, average income is plotted along the horizontal axis and measured by GDP per capita. While the average income is $1,750 in Ethiopia, in Switzerland it’s around $69,000 — this is after adjusting for differences in cost of living.

Because standards of living are so different, richer countries set their own national poverty lines much higher, to measure poverty in a way that is informative and relevant to their citizens' incomes.

The scatter plot captures this insight. As we can see, richer countries (higher GDP per capita along the horizontal axis) tend to set much higher national poverty lines (higher position along the vertical axis).

In Switzerland, a person is considered in poverty if they live on less than the equivalent of roughly $36 per day; in Ethiopia, the national poverty line is around $2 per day.

→ Read more in our page on global poverty. If you are looking for more details on this Data Insight specifically, you can find it in the study on which it is based: Joliffe et al. (2022).

Not all countries have data on how common mental illnesses are in the population. In fact, for many mental illnesses, only very few countries have this data.

This means global estimates of mental illnesses have wide uncertainties, and many people don’t get the help they need.

This chart shows, for each mental illness, the number of countries that had data in any year since 1980 on the prevalence of that mental illness in the general population.

This is from the IHME’s Global Burden of Disease study, a large global dataset presenting global estimates for various health conditions.

As you can see, data on conditions such as attention-deficit hyperactivity disorder, cannabis use disorder, and major depressive disorder come from a significant number of countries.

But data on others — such as bipolar disorder, autism spectrum disorders, and anorexia nervosa — came from far fewer countries.

With this large knowledge gap, the world is limited in making progress against many mental illnesses.

Read more →

Moore's law was first described in 1965 by Gordon E. Moore, the co-founder of Intel. He observed that the number of transistors in an integrated circuit doubled every two years.

This trend has continued over the last half century, and Moore’s predictions have remained surprisingly close to reality.

The chart shows data collected by computational scientist Karl Rupp on the number of transistors per microprocessor over the last 50 years. The data is plotted on a logarithmic scale on the vertical axis. The line follows a straight path, indicating stable exponential growth.

The average transistor count per microprocessor in 1971 was 2,308. In 2021, it was 58.2 billion. That's an average doubling time of 2.03 years — extremely close to Moore’s law.

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In recent years, there has been a notable shift towards artificial intelligence (AI) systems focused on language. They have outpaced advancements in other sectors like image recognition, gaming, and biology.

This is shown in the chart, which shows the number of AI systems considered notable by Epoch researchers.

The shift is primarily due to technical advancements in AI algorithms, particularly the introduction of “transformers” around 2017. As shown in the chart, the rapid development of language-based AI systems began around this time.

Transformers have radically changed natural language processing by evaluating chunks of text — “tokens” — instead of focusing on one word at a time. For example, by considering the whole sentence "The bank can ensure your money is safe", transformers can quickly discern that "bank" refers to a financial institution, not the side of a river.

This capability has significantly enhanced AI's ability in complex language tasks, improving machine translation and text generation, and making interactions more intuitive and effective.

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