In international statistics, immigrants are people who have lived for more than one year in a country other than the one where they were born.

Between 1990 and 2020, the share of immigrants in high-income countries doubled, rising from around 7% to 14%. This means that today, one in seven people in high-income countries was born in a different country.

High-income countries often attract migrants with better living conditions, including higher wages, stable political environments, and better public services. In turn, migration has become a crucial driver of population growth in these countries: without migration, the population of high-income countries would have declined since 2020.

This growth is much quicker than in other parts of the world. In contrast, the global share of migrants increased only slightly, with less than one percentage point.

Explore the percentage of immigrants in all countries →

The share of electricity produced by solar and wind in Poland almost doubled in just two years. In 2021, these renewable sources produced just 11% of its power; by 2023, this was 21%.

You can see this growth in the chart above, based on electricity data from Ember.

Poland still has one of the most coal-intensive electricity mixes in Europe, with coal producing 61% of its power. The country has committed to moving away from coal in the next few decades; growing solar and wind generation will play a key role in this.

Explore energy sources across the world in our Data Explorer →

This chart shows the share of people who consider friendships “very important” in their lives.

There are clear differences between countries: Northern Ireland (70%) and Sweden (65%) rank highest, and the United States (51%) and Indonesia (42%) are near the middle. In comparison, in Peru (17%) and Myanmar (12%), smaller shares of the population say that friendship is very important to them.

These differences suggest that the value people assign to different relationships varies significantly across cultures. In some societies, friendships might hold a central role in everyday life, whereas in others, people might place greater importance on family, work, or personal independence.

It's worth keeping in mind that such surveys don't only capture people's different views on friendship but also how they communicate their views when asked in surveys. For example, in some countries, people might be quicker to call something very important than in others.

Explore more data on the importance of friendships →

Rich countries spend, on average, the equivalent of $6,200 per person on healthcare. This includes public and private expenditures.

In low-income countries, the equivalent expenditure is only around $100 per person on average.

This is based on spending data from the World Health Organization’s Global Health Observatory, which you can see in the chart across levels of income.

That means rich countries spend 60 times as much on healthcare per person as the poorest countries. Therefore, it’s unsurprising that life expectancy and other essential health outcomes are far worse in low-income countries.

Explore more data and research on healthcare spending and outcomes →

Certain pathogens, like viruses and bacteria, can cause long-term inflammation or directly damage DNA in ways that eventually lead to cancer.

For example, hepatitis B and C viruses are key drivers of liver cancer. Some types of the human papillomavirus are responsible for cervical cancer. The bacterium H. pylori can cause stomach ulcers and cancers.

The International Agency for Research on Cancer estimates that around 13% of cancers overall are directly caused by infections, as the chart shows.

For some cancer types, they estimate that infections cause nearly all cases. They’re listed at the top of the chart and include cervical cancer, adult T-cell leukemia and lymphoma, and non-cardia stomach cancer.

This is an area where prevention can be very powerful: by tackling the infections that cause them, we can stop these cancers before they start.

Vaccines for human papillomavirus and hepatitis B have already been developed and have lowered cancer rates in younger generations. Additionally, antibiotics for H. pylori, antiviral treatments, and improved hygiene can dramatically reduce the risks of other infections.

I recently wrote an article about the virus that causes cervical cancer and how vaccines can eliminate it. You can read it here →

There are considerable differences in access to healthcare across the world.

Rich countries have around ten times as many doctors per person as poor countries. You can see this in this chart, which shows the number of medical doctors per 1,000 people in a population. This includes generalist physicians as well as specialists.

The global average is around 1.7 doctors per 1,000. In low-income countries, the figure is around five times lower.

Explore more data on healthcare spending and access →

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 →