average life expectancy means nothing when looking at things like social security .
life expectancy has many ways of measuring it depending what you want to illustrate .
life expectancy always has to be looked at as compared to a group and as the group gets older and older average life expectancy shifts . so as an example :
1-in-10 people born in 2014 is expected to die prior to age 60 (i.e., 90% are still alive), but beyond that point, the rate of death begins to increase substantially. However, over 60% of children born in 2014 are still expected to be alive when the cohort reaches their “life expectancy” (i.e., average age at death) of 79. The median (age 83) is equivalent to the 50th percentile, and the mode (89) is roughly around the 30th percentile. By age 100, only 2% of people born in 2014 are expected to still be alive.
so you can see as you get older and the sickly or those who have an early death in the cards are weeded out the odds of going on older increase . in this case life expectancy runs from 79- 89.
the old days had 65 as expectancy from birth but as an aging group is was much older back then .