Right, which puts the average at 48. A perfect time for wisdom teeth to take you out. The statistical language people use about talking about lifespan in before-times is rotten! That whole paragraph lays it out in its mathematical glory.
> For even wealthy landholding males, average life expectancy was about 31 years, rising to 48 years for those who made it to their twenties.
Even for wealthy families infant mortality was a problem.
on edit: they said factor out all the early childhood deaths - which probably aren't factored out for 'average' life expectancy.