Life expectancy is a demographic measure of the average time an individual is assumed to live based on the year of its birth, its current age, and other demographic factors, including gender. In the Bronze Age, life expectancy was just 26 years. In ancient Greece, people lived on an average of 28 years. Even in 1800, life expectancy was around 30 years in western Europe. Half of the kids died before age ten. They died because of what are now diseases or medical problems that are easy to treat now global. In societies with a life expectancy of 30, for instance, may have few people dying at precisely 30: most will die before 20 or after 45. In 1900 world average life expectancy was 31 years, in 1950 – 48 years. The 2017 world life expectancy was 72.2 years. Nevertheless, life expectancy is very various in the nations of the world . Nowadays, life expectancy in the Central African Republic is about 53, while life expectancy in Japan is about 85. Female human life expectancy is noticeably ...