What is the fine-grained topic of the following text: Martha Lauzen, the executive director of the Center for the Study of Women in Television and Film and a professor at San Diego State University, cited research showing that women accounted for 8 percent of directors working on the top 250-grossing movies of 2018, down one percentage point from 1998. Only return the topic.
Representation of women as directors in top-grossing movies