The Border House has posted scans of the results of last year's Game Developer Magazine survey, which is about as thorough examination of the demographics of the video game business as you can get.
It's interesting on many levels, firstly for seeing how much developers get paid, but then for seeing how many women there are in the industry.
Hint: there aren't many.
As you can see, most fields in the industry have around 10-20% female representation. Some go as low as 5%. And those who are in the trade are paid significantly less than their male counterparts.
There's an argument that this is because women have only recently begun to enter the video game workforce in serious numbers, meaning they'll mostly be at more junior positions, meaning that on surveys like this their numbers won't be skewed by senior management/developers.
You can check out all the figures here. A word of advice if you want to get rich: get into the business side. And...be a man when you do it :\
The 2013 Game Developer Gender Wage Gap [The Border House]