Groups i've been involved in:
A: 7 regular women, 10 regular men, ~6 drop-in women, ~10 drop-in men (male GM)
B: 5 women, 1 man (female GM)
C: 3 men, one woman (male GM)
D: 3 men, 3 women (male GM)
E: 4 men, 2 women (male GM)
F: 6 men, 3 women (male GM)
G: 2 men, 1 woman (male GM)
H: 4 men
I: 4 men, 1 woman (female GM)
J: 4 men, 1 woman (all took turns GMing)
K: 4 men
L: 6 men, 4 women (male GM)
Some overlap:
C&D, D&E, A&B, H&E, H&I,
Significant overlap:
G&A, J&K
So, approximating the overlaps, i've personally gamed with around 27 men and 19 women on an ongoing basis--i'm not counting convention games, nor the huge number of very-short-lived games i've been involved in (many of which i've probably forgotten). And i may not be counting all the long-lived games, nor remembering every person (especially in that first one), so assume i've undercounted significantly. Of regular RPers, that'd skew more towards men--i've probably forgotten more men than women. Of total, i'm not sure--i've seen a *lot* of women & girls come and go at the gaming table, giving it a try--if i include all of them, i might have actually gamed with more women/girls than men/boys, over the years. From talking to other RPers, both those i've played with and those i haven't, my experiences are atypical, but not radical--most groups i've encountered/heard about have at least one woman per 5 players, and all but one that i'm aware of have at least 2 women.
Anyway, not quite the question asked, but i figure my total gaming experience is a lot more useful in establishing some demographic approximations than my personal gender is.