Lets look further at the picture above. In today's economy the higher paid jobs are more on the left side with engineering and the math heavy sciences. Those are the sciences where woman are vastly underrepresented.
Sources:http://www.nytimes.com/2011/11/06/education/edlife/where-the-women-are-biology.html?_r=0
http://www.ascd.org/publications/educational-leadership/sept09/vol67/num01/Encouraging-Girls-to-Pursue-Math-and-Science.aspx