http://www.nytimes.com/interactive/2012/08/05/sports/olympics/the-100-meter-dash-one-race-every-medalist-ever.html
They invested a lot of money it seems, as here you have the same engine applied to Swimming.
And that's just an introduction to a wonderful blog about charts, called Junk Charts. The discussion of the Olympic charts is found here. And this is a nice appreciation of Kenworthy's work.
