It is undoubtedly most famous for being the home of the Pope.
But Vatican City has another claim to fame: it has the oldest population in the world.
The inhabitants of the microstate, surrounded by Rome, have an average age of 57.7 years.
By comparison, in Niger the figure is only 14.5, making it the youngest country in the world.
The global average for 2021 was 30, according to statistics from the University of Oxford-backed platform Our world in data and published as an interactive map that you can use here.
Meanwhile, Britain and the US ranked 53rd and 73rd respectively.
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The Vatican in Rome has the oldest population in the world with an average age of 57.7 years
The median age serves as an indicator of the age distribution of a population.
In its simplest form, it is calculated by counting everyone’s age and then noting how old the person in the middle is.
In contrast, the average would be arrived at by adding everyone’s age and dividing it by the number of people living there.
A higher median figure usually indicates that a country is richer, while lower ages usually indicate countries experiencing population growth.
In the Vatican, almost all of the 800 residents are priests and nuns who were granted citizenship by the Pope or papal authority because they were influential or important to Catholicism, making the population older.
After the Vatican come Monaco (54.5 years), the island of Saint Helena in the Atlantic Ocean (50.9), Japan (48.4) and Italy (46.8).
Portugal (45), Germany (44.9) and Greece (44.7) are all in the top 20 oldest populations.
But Britain does not fall into this category. With an average age of 39.6 years, the country ranks 53rd.
Meanwhile, the US comes in with a younger population at 37.7 and ranks 73rd in the world.
Countries with the youngest populations
- Nigeria: 14.5
- Central African Republic: 14.7
- Chad: 15
- Mali: 15.1
- Somalia: 15.2
- Burundi: 15.6
- Democratic Republic of Congo: 15.6
- Uganda: 15.9
- South Sudan: 16.1
- Angola: 16.2
- Mayotte: 16.5
- Burkina Faso: 16.6
- Afghanistan: 16.7
- Gambia: 16.8
- Malawi: 16.8
- Mozambique: 16.8
- Tanzania: 16.8
- Zambia: 16.9
- Nigeria: 17
- Benin: 17.5
Source: Our world in data
Countries with the oldest populations
- Vatican: 57.7
- Monaco: 54.5
- Saint Helena: 50.9
- Japan: 48.4
- Italy: 46.8
- Sint Maarten (Dutch part):46.5
- Martinique: 46.3
- San Marino: 46.3
- Isle of Man: 45.3
- Portugal: 45
- Bermuda: 44.9
- Germany: 44.9
- Hong Kong: 44.9
- Greece: 44.7
- Bulgaria: 44.5
- Puerto Rico: 44
- Spain: 43.9
- Croatia: 43.7
- Liechtenstein: 43.7
- Lithuania: 43.7
Source: Our world in data
The younger population may be due to the fact that Britain and the US have higher fertility rates than countries such as Japan, Italy and Greece, reducing the average age.
The UK had a birth rate of 10.1 per 1,000 inhabitants in 2021 and the US had 11.1 births. By comparison, it was just 6.9 in Italy and 6.6 in Japan, data show.
At the other end of the scale, after Niger, the Central African Republic (14.7), Chad (15) and Mali (15.1) have the youngest populations.
Such figures are caused by the fact that Africa is the fastest growing continent in the world, according to the United Nations. She expects that between now and 2050, more than half of the world’s population growth will take place in Africa.
Niger, which has the youngest population in the world, has the highest birth rate in the world, with the average woman having 7.2 children, according to the Population Reference Bureau.
The statistics agency attributes this to the fact that women marry young – which extends their childbearing age – and that only one in ten women use contraception.
But rather than because of wealth, some countries have a higher average age because they have seen a decline in birth rates.
Japan, for example, has an average age of 48.4 years, making it the fourth oldest country in the world. But the population dropped by 800,000 people in 2022.
Researchers say countries with a lower average age tend to have higher population growth rates, which is shown here with the correlation between average age and birth rate
Niger (pictured) has the youngest population in the world and the highest birth rate in the world, with the average woman having 7.2 children according to the Population Reference Bureau’s 2018 world population data sheet
This trend – labeled a crisis by officials – is attributed to people getting married later and choosing to have fewer children due to financial pressures.
There are fears that other countries will follow the same pattern.
The birth rate in developed countries has been falling for years, with the average woman having two and a half children in 2020, compared to five fifty years ago.
Higher levels of education and contraception and more women entering the workplace are thought to be behind these worrying trends.
Experts fear society will have “more grandparents than grandchildren” and face a “huge number” of challenges, such as too few young people to work, pay taxes and care for the elderly.
Researchers at Our World in Data noted that 2018 was the first time there were more people around the world who are over 64 years old than there are children under 5 years old.
“As the global population of people over 64 years of age will continue to grow, it is clear that we are moving towards an aging world,” it added.