Women as leads in Hollywood's top-grossing 2017 films aren't just the exception, but the number is down compared to the year before, although women of colour are seeing a slight increase on screen, according to a new study.

Research from San Diego State University's Center for the Study of Women in Television and Film reports that 24 per cent of lead roles in the 100 top-grossing films of 2017 belonged to women. The number represents a drop — not a gain — of five percentage points compared to 2016.

"I suspect many movie-goers will find this result surprising, given women's visibility as lead characters in films such as Star Wars: The Last Jedi, Beauty and the Beast, and Wonder Woman, the three top-grossing films last year," executive director Martha Lauzen told CBC News.

Daisy Ridley, starring as Rey in Star Wars: The Last Jedi, was one of few female protagonists in 2017's top-grossing films, according to research from San Diego State University. (Walt Disney Studios)

Change slow, if at all

The study, released Thursday, analyzed 2,361 characters appearing in films that led the 2017 box office in the U.S. and Canada, not including foreign films. The website Box Office Mojo provided the financial data.

Overall, women accounted for 37 per cent of major characters, compared to 63 per cent who were men. Major characters were defined as those appearing in more than one scene and instrumental to the storyline and also includes the lead characters. The figure showed no change compared to the year prior.

While the push for gender equality through recent movements such as Time's Up and #MeToo have sparked more conversations and debate, it could be years before substantial change translates to the big screen, since films typically take several years to make.

"In an awards season when talk about women and gender has been top of mind, we need to separate hyperbole from reality," said Lauzen. "The numbers do not yet reflect claims of a tectonic or massive shift in the film industry."

In films with at least one woman director or writer, however, the female presence in major roles on screen was higher, at 45 per cent.

The study also pointed out that women were more likely to have main roles on screen when at least one director or writer was a woman. Pitch Perfect 3, which was among 2017's highest grossing films and had a mainly female cast, was co-written by Kay Cannon. (Universal Pictures)

Slight gains in diversity

There was one increase worth noting, albeit small.

The number of women of colour on screen in top films went up from 2016 to 2017 — nominally:

The percentage of black women increased from 14 per cent of women on screen in 2016 to 16 per cent in 2017.

Latinas went from three per cent in 2016 to seven per cent in 2017, more than doubling.

Asian women went up from six per cent in 2016 to seven per cent in 2017.

Black women saw a slight increase on screen compared to 2016, of two percentage points. From left to right: Larenz Tate, Jada Pinkett Smith, Kofi Siriboe, Queen Latifah, Will Packer, Tiffany Haddish, Malcolm Lee and Regina Hall starred in the female-led movie Girls Trip. (Jonathan Bachman/Getty Images)

In addition to Star Wars: The Last Jedi, Beauty and the Beast, and Wonder Woman, the highest-earning 2017 films domestically rounding out the top 10 were: Guardians of the Galaxy Vol. 2, Jumanji: Welcome to the Jungle, Spider-Man: Homecoming, It, Thor: Ragnarok, Despicable Me 3 and Justice League.