[dredmorbius]

There likely is no average available, as coronors, undertakers, public health departments, and general statistics were poorly kept. So if rigorous comprehensive data are your requirement, you'll likely be disappointed.

What data were available favoured the wearthly, and from them and other, nonstatistical, contemporaneous accounts, it is apparently clear enough to note that the wealthy lived longer lives than the bulk of the population

Many of the poor who died, particularly infants, children, and women, may have left no documentary trace at all.