In my answer to this question regarding requirements for female titles I quoted the mean and standard deviation for male and female ratings for standard chess in the then current FIDE rating list. These were:
Female
Mean = 1505, standard deviation = 339
Male
Mean = 1675, standard deviation = 346
In the comments David pointed out:
I don't think the average rating of men and women is a relevant statistic at all. For starters, female players are on average much younger, so we should correct for that.
He makes a very good point.
A fairer comparison would be to look at mean and standard deviation for the two sexes for the U20, 20-50 and over 50 age groups, roughly juniors, adults and seniors
So, what are these figures for male and female for these three age groups?