Demographics: life expectancy

Self-tutoring about actuarial resources: the tutor mentions an idea about life expectancy.

In my post from yesterday I mention an actuarial table, here. Said table can be used to discover the proportion of females, or males, in the US, who survive to a certain age.

The life expectancy, from age 0, of a male is given on said table as 74.74 years. Yet, at age 79, it seems, from the table, that 50,479 males (out of 100,000 born) remain alive; at age 80, it’s 47,715.

Perhaps life expectancy is defined in a way not related to the actuarial table. However, to my mind, the table’s survivor numbers suggest a possible interpretation that the life expectancy, for males in the US, is 79-80.

Interesting, eh?