Interesting.
First of all, my formal first name and its most common diminuitive (which I use) are vastly different in their distribution.
Secondly, my wife's name ain't even on the map. (She'll be pleased about that, I'm sure).
Third, we put some effort into picking not-extremely-popular-but-normal-sounding names for both of our daughters, and yet each of them is on an upward trend since the 60s sharp upward spike since about 1990 or so. I guess we unconsiously managed to tap into the gestalt. What the hell's the point of never watching any TV when stuff like this happens?