Report says the number of registered users of shared bikes in the world was nearly 400 million as of December 2017, China News reported.

The report was jointly released by the Scientific Research Institute under China’s Ministry of Transport and Ofo, one of China’s major bike-sharing players, on Jan. 17.

According to the report, there are altogether 23 million such bikes in the bike-sharing market, with 400 million registered users in 304 cities across the world.

The report pointed out that Ofo and Mobike are the two biggest shared bike companies in China, with 90 percent of the industry’s orders.

Short distance bicyclers, riding 500 meters to 2 kilometers per ride for 6 to 20 minutes, take up over half of all the bike users, the report says.

The number of male users of shared bikes surpasses that of female users, accounting for 57 percent and 43 percent, respectively, and the number of bicycle users in southern China is larger than that in northern China.

In addition, the report noted that the service contributed a lot to energy conservation and emission reduction.

Taking Ofo as an example, its users rode about 11.75 billion kilometers in 2017, equivalent to saving 590,000 tons of gasoline, reducing 2.59 million tons of carbon dioxide emissions, and planting 2.59 billion trees.

Shenzhen, Chengdu, and Beijing were ranked the top three among all Chinese cities concerning use of shared bikes in 2017, the report shows.