Photo taken on May 9, 2015 shows tourists attending a grand ceremony at the Mausoleum of Genghis Khan in Ejin Horo Banner, north China's Inner Mongolia Autonomous Region. According to the Statistical Communique of China on the 2015 National Economic and Social Development released by the National Bureau of Statistics Monday, the year 2015 registered four billion domestic tourists, up 10.5 percent over the previous year. The revenue from domestic tourism totaled 3,419.5 billion RMB, up 13.1 percent. (Xinhua/Lian Zhen)