When it comes to women in CFO roles at Fortune 500 companies, the faces may change, but the overall number stays essentially constant. As of June 1, there were 45 female finance chiefs in the Fortune 500 (see listing below). That’s just one more than in 2010 and 2009, for a percentage of 9%.

Ten women dropped off the list since last year and 11 joined the ranking, either because they were promoted or hired or because their companies made the Fortune 500 this year. Two companies, SuperValu and TIAA-CREF, replaced their departing female CFOs with other women. SuperValu promoted Sherry Smith to CFO after Pamela Knous left, and TIAA-CREF hired Gina Wilson to replace former finance chief Georganne Proctor.

Of the 11 women who joined the list, some were internal hires, like Safra Catz, recently promoted to CFO at Oracle after holding the president position there for years and the CFO role before that. Others came from outside, like Irene Esteves, former CFO of XL Group, who was recently appointed to CFO at Time Warner Cable.

Although women make up 56% of undergraduate accounting majors and almost 62% of accountants and auditors, they rarely make it to high-level finance roles like treasurer, controller, or CFO. But some companies — many of which have female CFOs — have much higher percentages of women in top finance positions. You can read about these companies’ efforts to help women ascend in finance in the upcoming July/August issue of CFO magazine.