It’s been a groundbreaking year for women in business according to the Forbes Magazine. IBM appointed its first female CEO in Ginni Rometty. Sheryl Sandberg led Facebook through a much-anticipated IPO. Irene Rosenfeld is busy splitting Kraft into two public companies, and Marissa Mayer jumped from a top Google exec to the CEO seat at Yahoo. See who made the top 20 and where they fall on the rankings.