How is a woman's role diminished in the TV and film industry?

Source: 2012 .A guy with some girls and a statistic. [Photograph]. Retrieve from http://www.motherjones.com/media/2012/11/geena-davis-institute-women-girls-are-stereotyped-sexualized-hollywood

San Diego State University annually collects data of women's positions in the top films of the year. The women to men ratio in tv and film is pretty even, but the roles women play in movies and tv-shows are significantly different. In 2013’s top 100 films females comprised 15% of protagonists, 29% of major characters, and 30% of all speaking characters.  Often roles of women in TV and films are stereotyped and/or sexualized.  Behind the scene roles in films are also dominated by men. Overall, women accounted for 16% of all directors, executive producers, producers, writers, cinematographers, and editors.