Average Speed of New World Records

I was taking a look at a feature on NYTimes.com showing the 38 new world records set at the 2012 Summer Olympics. Several of them happen to have been broken the day before by the same athlete, but in the end: it's still an impressive figure.

I thought it would be nice to see how fast people were moving, on average, while breaking the record. I didn't care much about the cycling records (not discounting you cyclists out there) - just purely human powered movement. This was simply due to the history of running and swimming. We've been doing both for quite a while.

Here's how the new speed records (track and swim) broken down in average speed: