I’ve been going through the medal statistics in London 2012 Olympics recently. I was planning to present some extra charts, such as medal-per-milli-population or medal-vs-GDP. However, it’s a little boring to present the same kind of charts. Thus, I’d like to look into some particular sports in detail. The first one is the world record progression in women 400 metres individual medley, in which the Chinese swimmer Shiwen Ye just broke the world record by Stephanie Rice in 2008. It seems that since 1980 the record become more difficult to break than before (for the interactive chart, please click here).