BEIJING, April 19 (Xinhua) -- Chinese cinemagoers watched many more documentaries in 2017 thanks to high-profile productions and new online promotions.

A total of 16 documentaries hit the big screens in 2017, and grossed 269 million yuan (42.84 million U.S. dollars), according to an annual report published by the Documentary Center, Beijing Normal University, Wednesday.

Ten of the documentaries were domestically produced and collected box office of 263 million yuan, up 237 percent year on year, while the six imported films grossed about 6.12 million yuan, according to the report.

Among them, "Twenty Two," a documentary about "comfort women" forced into sexual slavery by the Japanese during World War II, took the highest box office of 170 million yuan.

There were also two other documentaries earning more than 30 million yuan each.

The benchmark box office of 30 million yuan was set by the documentary "Zhou Enlai's Diplomatic Career" in 1998. Until 2016, no documentary had broken that record.

In 2016, "Born in China" reported a box office of 66.54 million yuan.

"The documentary market indeed saw a breakthrough last year," said Zhang Tongdao, head of the the Documentary Center, Beijing Normal University.

A high-profile production like "Twenty Two" triggered a snowballl effect to draw more attention to other documentaries, Zhang said.

Compared with commercial productions, documentaries producers have long struggled for a limited chance of screening in cinemas due to relatively niche audience.

The uncertainty of audience feedback has pushed cinemas away from documentaries, said Liu Zhongbo, associate professor of Tianjin-based Nankai University.

"Many documentaries can not be judged by the box office in the first three screening days. They might have a much longer buildup but continuous inflow of viewers," Liu said.

In some cases, in the earlier days of screening when cinemas allocated enough screens for a documentary, audience may not haven show up but when the screens are reduced, the viewers suddenly surge, according to Liu.

Crowdfunding on the Internet has offered a new solution. Some service providers have launched a crowdfunding-like programs, in which audience can book tickets for a film in a certain cinema, though it is not actually scheduled to be screened. When ticket buyers reach a certain number, the service provider will approach the cinema to arrange a screening.

Most films "crowdfunded" are art films and documentaries that do not have enough budget for promotion and will not be accepted by cinemas for a normal screening, Liu said.

"Through such innovative online services, these productions can still find their audience and hit the screen," he said, adding that this was very useful to supplement the mainstream screening system and particularly conducive to production and the distribution of documentaries.

In 2017, at least three documentaries tried this new promotion model and were screened on and off but over a much longer period.