Average age of population

the average age of the entity’s population. It is calculated as the sum of the years of the population divided by the total population of the entity in the reference year. For example, a person aged 42 years in the reference year ‘counts’ for 42 years of life.该实体人口的平均年龄。其计算方式为：在基准年（reference year）下，将该实体全体人口的年龄年数之和除以该实体的总人口数。例如，在基准年中一名42岁的个体，将按42年的生命时长计入年龄年数总和。