The expression "raising average life expectancy by one year" first appeared in this year's Government Work Report. But many people don't know the exact meaning of raising average life expectancy from 73.5 to 74.5 years that is one of the specific objectives of the 12th Five-Year Plan (2011-2015).

Guo Ping, a research scholar with China Research Center on Aging, says life expectancy is a widely accepted index to evaluate the health status of people of a country or region based on the life table. Generally, it uses census data and death registrations to calculate the prospective life span of people, because it is very difficult to track the "birth-to-death" journey of each and every citizen.

Genetic factors notwithstanding, social stability is theoretically the prime influencing factor of average life expectancy. Economic development, accompanied by improvements in the fields of medical treatment and public health, has a significant impact on average life expectancy, which can be demonstrated by China's experience.