I've done a good bit of digging around on that and other genealogy sites too. There are a few things that strike you immediately. The number of women who died in childbirth. The number of little babies who died in the first year (and to a lesser extent kids under the age of 10) and finally just how many kids they had. Holy Crap! They were cranking out a good 8-9 kids who lived per generation. Once you see that you come to quickly understand how so few people in the 1600s could turn into so many by the 20th century.
One of my grandfathers was 6 when his mother died (aged 38, shortly after giving birth)--4 of his siblings died in childhood. My other grandfather was 19 when his mother died at 41 (of cancer).
One of my ancestors born in the 1760s or 1770s was one of ten children but the only one who lived to adulthood.