Not going into which country or anything, but a country has a statistical life expectancy of 71-75 years, BUT an average age of 17.something years.
The question is, how is it possible to reach such disparate numbers? With an average age that low, how can you get a reasonable assumption that you can live to 71-75 years of age?
I can see that if you have a huge influx of young people, or a baby boom of 17 years and still going strong, but assuming that isn't the case... how?
(Source of numbers: CIA world factbook)