How is the average life expectancy of China people calculated at 75 years?

A series of mathematical formulas are used to calculate the average life expectancy of the population. If described in words, the average life expectancy of the population is calculated by following up a group of people born at the same time, recording their deaths at all ages until the end of the last person's life, and then calculating the average life expectancy of the population according to the number of people who live to all ages.

Use the average life expectancy of this group of people to assume that the average life expectancy of a generation is the average life expectancy. In fact, it is very difficult to track the whole life process of a group of people born at the same time.

In practical calculation, we can often replace the mortality level of the same generation at different ages with the mortality level of the population at all ages in the same year, and then calculate the average number of people at all ages, thus calculating the average life expectancy of the population in that year. Therefore, the average life expectancy of the population is related to the contemporary mortality level.

Extended data

The length of life is influenced by many factors. The strength of innate endowment, acquired training, living conditions, social system, economic conditions, medical and health conditions, etc. Will have an impact on human life.

There is no scientific basis for accurately estimating an exact upper limit of life. Now the life span of human beings is changing. Physiologically speaking, life span is no longer a fixed constant, but whether it can be extended indefinitely remains to be scientifically studied. As the founder of material civilization and spiritual civilization, human beings have been breaking the limits of life for a long time.

According to the data of the sixth census, the average life expectancy in Shanghai, Beijing and other places has exceeded 80 years, and that in 26 provinces (cities, districts) has exceeded 70 years.

It is worth mentioning that since 20 12, China has become the region with the highest average life expectancy in the world, with an average life expectancy of 83.98 years in 20 14.

Baidu encyclopedia-average life expectancy of population