I find the guy:female (47:5) both amusing, and sadly surprising (Sad in that I was surprised to find almost 10% of the respondents are female. I have a really hard time recruiting women into my campaigns as active participants.)
Anyway, for me I would have rate my character gender as 94% same [male], 5% unmentioned [genderless or gender irrelevant] (warforged, treant, robot, androgynous rabid psychotic murderous agent of death, zombie, etc), and 1% opposite [female].
Really I only pick female if the setting demands (or at least heavily suggests) it, and the unmentioned category probably still falls toward male personalities most of the time.
I think it may be in part because I am spending so much effort being someone else in most other ways, that being a different gender is not interesting enough to offset the cost of the amount of effort I would need to invest to stay in character as a female and approach situations appropriately. Kind of like the Sorceress in "The Dorkness Rising" (go see it if you haven't already).
Similarly, I rarely play arachnids, masonry, fashionista, squid, or cats.