The global number of people aged 65 years and older is set to double within the next thirty years

Homicide rates measure the number of intentional, illegal killings per 100,000 people annually.

Since 2000, rates in the United States have fluctuated around 6 homicides per 100,000. They fell from a peak of 6.7 in 2001 to 4.4 in 2014 but climbed back to 6.4 in 2022. Preliminary data suggests they fell back to 5.7 in 2023.

Over the same period, Europe’s rates fell from nearly 8 per 100,000 people in 2000 to just above 2 — a drop of almost three-quarters.

Explore homicide rates in many more countries →

In some countries such as Japan, the United States, or South Korea, almost all households have air conditioning in their homes. In others, almost none do. This includes countries like India or South Africa where extreme heat is frequent.

In this chart, you can see the share of households that had air conditioning (AC) in 2018. This data comes from the International Energy Agency.

Paying for the upfront cost of an AC unit is a key barrier to adoption, so as incomes rise, more people get access to them.

Access to air conditioning is becoming increasingly important as the world warms and extreme heat becomes more common.

Read more about how populations can protect themselves against extreme heat →

Cancer death rates rise steeply with age.

The chart shows this for a wide range of cancers, including bladder, breast, colorectal, stomach, and prostate cancer. The data comes from the United States Centers for Disease Control and Prevention.

Long-term exposure to risk factors — such as smoking, radiation, and certain infections — damages our cells. This damage accumulates with age, increasing the chances of cancerous mutations. In addition, our cells’ ability to repair this damage also weakens, allowing the mutations to accumulate.

Cervical cancer has a slightly different shape: its risks rise at a much younger age and then slow down. This is because it is caused by the human papillomavirus (HPV), typically spread through sexual contact at younger ages. Without HPV, it’s very rare for this cancer to develop, and infection can be prevented with early vaccination.

Read more about the risks of cancer with age →

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 bring bad fortune, especially for their future husbands.

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 →

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 →

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 →

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 →