I completely agree that there were old people, i spend quite a lot of time in cemetery's and am always amazed to see the grave marker of a 90 year old, so I am not denying that. But you are describing 'life expectancy at age 5,' which is a different statistic entirely. Life expectancy at birth includes everyone. Yes, if a child made it to 5, their odds improved, and they might live to 55 or 60. But that does not change the fact that for every one of those survivors, there were several children and young adults who died early, pulling the average for everyone born down into the 30s or 40s. The cemetery shows the survivors—it hides the massive number of children who didn't make it.