How Did Life Expectancy Change in the 20th Century?

Life expectancy in rich countries increased by 30-40 years during the 20th century but seems to be leveling off. The United States Census, United Nations and OECD expect life expectancy to increase by only about seven years from 2000-2050 and by only about 13 years by 2100. Other experts say that this might be too conservative of an estimate, though, because most projections of changes in life expectancy are based on record life expectancy, or the highest life expectancy experienced by any country at a particular time.

More facts about life expectancy:

• One of the main reasons life expectancy increased so rapidly during the 20th century is because of the decline of chronic diseases. In the early 1900s, elderly people typically began experiencing chronic disease or bad health 10 years earlier than elderly people at the end of the century.


• Countries that have the highest life expectancies include Monaco, Macau, San Marino, Japan and Hong Kong. With the exception of Afghanistan, the lowest 39 countries in terms of life expectancy are all located in Africa. Other than Afghanistan, the countries with the lowest life expectancy outside of Africa are Haiti and Laos.


• As of 2010, the average global life expectancy was about 67 years. That's about a 36-year increase over the global life expectancy in 1900.