тут речь о децкой смертности:
The above chart shows the share of children surviving the first five years of their lives. It goes back to the year 1800. Health conditions in the time of our ancestors were such that more than 4 out of 10 newborns died before their fifth birthday. The historical estimates further suggest that it was the entire world that lived in poor conditions: there was relatively little variation between world regions, and even in the best-off countries of 1800 every third child perished.
картинки, не совсем картинки — по ним водите курсором пойнтера