Since the mid-1980s, more than 40 percent of law firm graduates have been women. So how come they make up less than 20 percent of equity partners in AmLaw 200 firms? That is one of the questions that the National Association of Women Lawyers (NAWL) answers with its eighth annual National Survey on Retention and Promotion of Women in Law Firms. The 92 firms responding to the survey identified two primary obstacles to female advancement: a perceived lack of business development on the part of firms and a lack of work …