Life expectancy measures the overall health of a population. While there are certain metrics like infant mortality that tracks deaths at a young age, life expectancy shows the average age of death for a population. This chart shows the life expectancy by decade.
One can gain many insights by looking at the trend of life expectancy over time. For one it answers the question of “how healthy is a society?”
For a baseline, the estimated life expectancy for a pre-modern, poor society was roughly 30 years.
As science, technology and health advances in a country, naturally the life expectancy will follow. You can see this trend in each country shown.
Life Expectancy by Decade
Despite massive world population growth since the 19th century, life expectancy has also risen.
The United States and United Kingdom both started out with a similar life expectancy in 1950. Since then the US has lagged a bit behind the UK in this aspect.
There could be many reasons behind this statistic, though the fact that the US has one of the highest obesity rates in the world certainly plays a factor.
On the other hand, Japan has one of the highest life expectancies in the world, despite starting out much lower than the US and UK post-World War II. Their culture has much to do with this.
Saudi Arabia is a country that started off much lower than others in 1950. As more aspects of their society became westernized, this number has shot up. Though it isn’t quite at the level of other nations yet, it has made tremendous progress.
Source: Macro Trends