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Daily Data Insights

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

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The chart titled "Share of births that are twins" displays the percentage of twin births over time, spanning from 1858 to 2021. The vertical axis represents the share of births that are twins, ranging from 0% to 2%.

There are five colored lines, each representing a different country: the United States, France, Canada, Australia, and England and Wales. Throughout the years, the percentage of twin births shows a noticeable increase in each of the countries shown, particularly from the 1980s.

A note on the chart indicates that delayed childbearing, alongside technologies such as IVF, has contributed to this rise in twin births. 

The data for this chart is sourced from the Human Multiple Births Database in 2024. The chart is credited under a Creative Commons BY license, and is published by Our World in Data.

The twin baby boom

The share of births that are twins has changed over time.

The chart shows data for France, Canada, the United States, and England & Wales in the Human Multiple Births Database.

As you can see, twin births have risen dramatically since the 1980s.

One reason is the use of reproductive technologies such as in vitro fertilization (IVF), which have made it possible for many more couples to conceive. During procedures like IVF, multiple eggs can be used at the same time to maximize the chances of a successful pregnancy, which can lead to twin births.

Another reason for the rise in twin births is that the average age of women at childbirth has risen. Older women are more likely to have twin births, even without using reproductive technologies.

Twin births are a chance event, but data shows they can also be influenced by societal changes and reproductive technologies.

Explore trends in twin births for other countries

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A line graph depicting the average number of days it took to install a gigawatt of solar energy capacity worldwide from 2001 to 2023. The vertical axis represents the number of days on a logarithmic scale, spanning from 1 to 1000 days. The horizontal axis indicates the years from 2001 to 2023. 

In 2004, the average time was about 1 year, which is marked on the graph. A downward trend shows significant decreases in installation time over the years. By 2010, it took under 30 days, and by 2015, just over 7 days. The most notable point is in 2023, where it dropped to about 1 day on average for installation. 

The data source is attributed to IRENA (2024), with calculation by Our World in Data, and the chart is identified as CC BY, indicating it is licensed for sharing and adaptation with appropriate credit.

In 2004, it took the world a year to add a gigawatt of solar power — now it takes a day

To mitigate the negative impacts of climate change, the world needs to quickly transition from fossil fuels to low-carbon energy sources such as solar power.

The chart shows how much this transition has accelerated in the last two decades.

In 2004, it took the world about a year to add one gigawatt of solar power capacity. By 2023, the same amount was added, on average, every single day.

For reference, a gigawatt of solar is enough to power approximately 200,000 homes in the US.

Much of this growth has been driven by China, which by 2023 accounted for about 43% of the cumulative installed capacity worldwide.

A big reason for this acceleration has been a large decrease in the price of solar panels. Since 2001, the price has dropped by about 95%, from $6.21 to $0.31 per watt.

Learn more about why renewables like solar became so cheap so fast

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A line graph titled "In some English-speaking countries, people value religion less than before" displays data from 1993 to 2022 on the share of people who consider religion "very important" or "rather important" in their lives. The graph features five lines, each representing a different country: 

- The United States, starting at 79% in 1993 and decreasing to 61% by 2022.
- Canada, beginning at 61% in 1993 and declining to 35%.
- Australia, initially at 48% and dropping to 29%.
- The United Kingdom, starting at 45% and falling to 33%.
- New Zealand, with a starting point of 38% and a slight decrease to 28%.

The Y-axis represents the percentage of respondents, while the X-axis marks the years from 1993 to 2022. A note on the survey question states: "Would you say [religion is] very important [in your life], rather important, not very important or not important at all?" The data source is cited as "Integrated Values Surveys (2022)" along with a Creative Commons BY attribution.

Religion has become less important in some English-speaking countries

Religion means less to people in some English-speaking countries than it did 30 years ago.

The chart shows a clear downward trend in the share of people who see religion as important in their lives. This is based on surveys across the US, UK, Canada, Australia, and New Zealand, from 1993 to 2022.

The United States stands out as the country with the highest percentage of people who consider religion important, though this has declined from 79% to 61%. The shift was even sharper in Canada, falling from 61% to 35%.

Religion was already less important to people in Australia, the UK, and New Zealand but in all three countries, this share dropped by more than a quarter.

Explore this data on the importance of religion for many more countries

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A timeline titled "The Golden Age of Antibiotics" shows when each antibiotic drug class was first available for medical use, with example antibiotics labeled. Classes are color-coded by their source: actinomycetes, other bacteria, fungi, or synthetic. Milestones include the first antibiotics (arsphenamines in 1910), as well as the discovery of many actinomycetes-derived antibiotics, such as streptomycin, and sulfonamides, penicillins, and tetracyclines. Data: Hutchings, Truman, Wilkinson (2019). Created by Saloni Dattani for Our World in Data.

Nearly two-thirds of antibiotics were introduced during the “golden age of antibiotics”

The “golden age of antibiotics” lasted from the early 1940s to the late 1960s. It was a period of rapid innovation that transformed medicine. As highlighted in this chart, nearly two-thirds of all antibiotic drug classes were introduced during this period.

Scientists explored natural sources — such as fungi and bacteria — and synthetic sources.

This led to breakthroughs in antibiotics derived from soil-dwelling bacteria, such as streptomycin, tetracyclines, and macrolides, and the mass production of penicillin, which Alexander Fleming discovered in 1928.

However, progress slowed after the 1970s as pharmaceutical companies shifted their focus to chronic diseases. Today, there is a renewed need for innovation to tackle antibiotic resistance.

Read my article on the golden age of antibiotics and how we can spark a new one →

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A line chart showing the global average life expectancy from 1900 to 2023. The vertical axis represents life expectancy in years, ranging from 0 to 80, while the horizontal axis indicates the years from 1900 to 2023. While average life expectancy was 32.0 years in 1900, it was 73.2 years in 2023.

In 1770, the average life expectancy was only 28.5 years, depicted at the lower end of the graph. By 2023, it had risen to 73.2 years, noted at the upper portion. Key points on the graph highlight this change. 

Data sources cited include UN WPP (2024), HMD (2024), Zijdeman et al. (2015), and Riley (2005). The information can be further accessed at OurWorldinData.org/life-expectancy. The graph is labeled with the text "Global average life expectancy has more than doubled," emphasizing the significant increase over the centuries.

Global average life expectancy has more than doubled since 1900

We can expect to live more than twice as long as our ancestors in 1900.

As the chart shows, global average life expectancy was just 32 years at the beginning of the 20th century.

This was a short life by today’s standards: in 2023, the average life expectancy had increased to 73 years. That’s 41 years longer.

This remarkable increase is due to improved living standards, like better nutrition and sanitation, and advances in healthcare, such as antibiotics and vaccines.

While large declines in child mortality have been crucial, they have not been the only reason for the increase in life expectancy; it has increased across all ages.

Read more in our article “Twice as long – life expectancy around the world”

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Bar chart showing the global lithium production by country in 2023. Australia leads with 48% of global production, followed by Chile at 24% and China at 18%. Argentina contributes 5.3%, Brazil 2.7%, Zimbabwe 1.9%, Canada 1.9%, and Portugal 0.21%. The chart highlights that Australia, China, and the "lithium triangle" (Chile, Argentina, and Bolivia) dominate lithium production.

The world’s lithium is mined in just a handful of countries

Lithium is a critical component in many industries, including pharmaceuticals, optics, ceramics, and glass. But it’s best known for its use in batteries. Most rechargeable batteries in mobile phones, laptops, and consumer electronics are made from lithium-ion chemistries.

It’s also receiving increasing attention as a critical mineral in batteries for electric cars and storage for renewable energy.

Just a handful of countries supply the world’s lithium. In the chart, you can see each country’s share of global mined production in 2023. Australia produced almost half. Combined with China, Chile, and Argentina, these four countries produced over 90% of the total.

Chile, Argentina, and Bolivia form the so-called “lithium triangle”, which are large lithium deposits that span across these three countries. While Bolivia has huge lithium resources, it has produced very little so far.

This data comes from the United States Geological Survey.

Explore which countries produce other critical minerals in our data explorer →

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A line chart that shows the global increase in 4G network coverage from 2015 to 2023. The x-axis represents years (2015 and 2023), while the y-axis shows coverage percentages. In 2015, North America had the highest coverage at 99%, followed by Europe (76%), Latin America (58%), and Asia (40%). Sub-Saharan Africa had the lowest at 11%. By 2023, North America and Europe reached 99%, Asia increased to 94%, Latin America to 91%, and Sub-Saharan Africa to 63%. Globally, coverage rose from 44% in 2015 to 90% in 2023, indicating that nearly 9-in-10 people worldwide are now within range of a 4G network. A note clarifies that network coverage does not imply usage.

Nine in ten people in the world were in the range of a 4G network in 2023

Internet access has grown rapidly over the last few decades. It lets us connect with people across countries and continents, helps students learn and apply for jobs, and is even the primary mode of banking in some parts of the world.

But having access to fast internet also matters. This is also changing quickly.

In 2015, less than half — 44% — of the world population was in the range of a 4G network. That figure is now 90%. In the chart, you can see that this has increased quickly across many regions. This data comes from the International Telecommunication Union.

Note that being in the range of a 4G network doesn’t mean that someone is using it. If people don’t have a mobile, computer, or service to connect, they might be in the range of a network but not online.

Explore more charts on technological change across the world →

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What share of children die before their fifth birthday?

What could be more tragic than the death of a young child? Child mortality, the death of children under the age of five, is still extremely common in our world today.

The historical data makes clear that it doesn’t have to be this way: it is possible for societies to protect their children and reduce child mortality to very low rates. For child mortality to reach low levels, many things have to go right at the same time: good healthcare, good nutrition, clean water and sanitation, maternal health, and high living standards. We can, therefore, think of child mortality as a proxy indicator of a country’s living conditions.

The chart shows our long-run data on child mortality, which allows you to see how child mortality has changed in countries around the world.

Explore and learn more about this data
Explore and learn more about this data

Share of population living in extreme povertyWorld Bank

Life expectancy at birthLong-run estimates collated from multiple sources by Our World in Data

Per capita CO₂ emissionsLong-run estimates from the Global Carbon Budget

GDP per capitaLong-run estimates from the Maddison Project Database

Share of people that are undernourishedFAO

Literacy rateLong-run estimates collated from multiple sources by Our World in Data

Share of the population with access to electricityWorld Bank

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