The Dave ratio
is a "law" similar to Moore's Law
in that it isn't really
a law but it often holds true.
The Dave ratio: the number of women in a technical (or geeky) profession is about equal to, or less than, the number of people named "Dave" in the same group.
While this may seem rather dumb, but you'd be surprised at how true it often is.
idea originally from a /. discussion