Fifty-two percent of Netflix films and series in 2018 and 2019 had girls or women in starring roles. And 35.7 percent of all Netflix leads during that span came from underrepresented groups, compared with 28 percent in the top 100 grossing theatrical films.

Those findings were released on Friday by the University of Southern California’s Annenberg Inclusion Initiative, which Netflix commissioned to look at its own U.S.-based scripted original films and series. The study analyzed 126 movies and 180 series released during 2018 and 2019.

“Notably, across 19 of 22 indicators we included in this study, Netflix demonstrated improvement across films and series from 2018 to 2019,” said Stacy L. Smith, who is the head of the initiative and has been studying representation in film and television since 2005, during an online symposium the company held to discuss the survey. She said Netflix had also increased the percentage of women onscreen and working as directors, screenwriters and producers; for Black cast and crew; and for women of color in leading roles.

Of the 130 directors of Netflix films in those two years, 25 percent were women in 2018 and 20.7 percent in 2019 — outpacing the feature films released theatrically by other studios over the same period.

While Netflix reflects gender equality in its leading roles in television series and films, when every speaking character is evaluated, those roles did not match what the country looks like from a gender and race perspective. Only 19.9 percent of all stories met that mark. For instance, 96 percent of stories did not have any women onscreen who identify as American Indian/Native Alaskan, and 68.3 percent of the content evaluated did not include a speaking role for a Latina. That number rose to 85 percent when it came to speaking roles for Middle Eastern/North African women.

Scott Stuber, Netflix’s film chief, acknowledged how crucial those kinds of small parts were to working actors.

“The SAG card is everything,” he said, referring to the Screen Actors Guild membership that performers earn by having roles in various projects. “That is the beginning of the dream. We have to be very active with our filmmakers and our casting directors to fix that. That’s the next great artist. That’s the next Viola Davis.”

According to the report, L.G.B.T.Q. characters at every level of film and television were marginalized, particularly transgender characters. And just 11.8 percent of L.G.B.T.Q. characters in leading roles were shown as parents.

“I was shocked that we are not doing great there,” said Bela Bajaria, the head of global TV for Netflix. “I feel like we are so active in our story lines. But the lack of gay parents in our shows, that’s a clear takeaway.”

According to Netflix’s chief executive Ted Sarandos, the company is committed to releasing a new report every two years through 2026.

“Our hope is to create a benchmark for ourselves, and more broadly across the industry,” he wrote in a blog post that accompanied the report.

The director and screenwriter Alan Yang said during the symposium that he was bullish on the future of inclusion in entertainment, especially at Netflix, which produced a series he created with Aziz Ansari, “Master of None,” and his feature film “Tigertail.”

“It’s going to improve a lot if Bela and Scott buy all the shows and films I pitch them,” Mr. Yang said with a laugh.