http://www.slate.com/articles/double_x/doublex/2015/01/women_on_corporate_boards_sheer_number_increases_can_t_fix_a_company_s_gender.html

There’s a persistent gender divide in the upper tier of most industries in the United States. The magic number seems to be just under 20 percent—that’s the percentage of women who are equity partners in law firms (17 percent), in Congress (18.7 percent), and on the boards of S&P 500 companies (19.2 percent). A new report from the research arm of Catalyst, a nonprofit devoted to expanding opportunities for women in business, compares the number of women on boards in the U.S. with the number of women on boards in several other countries, with the takeaway being that we’re failing here.