The same probably goes for all the other traits (blonde vs brunettes, cup sizes, and so on). At least they are pretty useless without a comparison to the average female population.
It is a hard problem. You could, for instance, divide by population to get a rate instead of an absolute number -- but then rural areas would have all the hotspots. Why? Because in areas with small samples, you're bound to get more variation and noise, so all the extremes will occur in areas where there are few people.
There are ways to adjust for that, but basically, you can't win:
I'm trying to make sense of Texas. There's 50 claiming San Antonio (Good Catholic Latinas Gone Bad?) and another 50 centered on land that is merely rural range (but with a little shack outside La Grange!). One from A&M and one from Baylor U. Who wants to claim they're from Lubbock?
Luckily there is a relevant xkcd: http://xkcd.com/1138/