Actually, I heard that the % of introverts in the male population was higher than for females. Additionally, this is only a piece of supporting evidence, but the #1 male type is ISTJ. #1 female type is ESFJ. (as far as population percentages go)Generally, men tend to be more extroverted than women, more sensing than women, more thinking than women and more judging than women - ST and NT types are probably more male-dominated, whilst SF and NF types are probably more female dominated.
My own anecdotal evidence also supports this. I know far more male I's than female I's.