Your hypothesis at least lines up with the big points in the data.<p>Computer science enrollment went through a huge boom and bust centered on 1984-1985. In a five year timespan the number of computer science majors increased by five times, before falling back to approximately half the peak.<p>The second big increase in computer science graduates was in 2005.<p>These both correspond with the major drops in the percentage by gender chart.<p>Points to you if you make a graph for us of the absolute historical Computer Science graduation rate by gender.