Fig. 2

The distribution of investigational centres in China. Notes: 01, Anhui Province; 02, Beijing City; 03, Fujian Province; 04, Gansu Province; 05, Guangdong Province; 06, Guangxi Autonomous; 07, Guizhou Province; 08, Hainan Province; 09, Hebei Province; 10, Henan Province; 11, Heilongjiang Province; 12, Hubei Province; 13, Hunan Province; 14, Jilin Province; 15, Jiangsu Province; 16, Jiangxi Province; 17, Liaoning Province; 18, Inner Mongolia Autonomous; 19, Qinghai Province; 20 Shandong Province; 21, Shanxi Province; 22, Shaanxi Province; 23, Shanghai City; 24, Sichuan Province; 25, Tianjin City; 26, Xinjiang Autonomous; 27, Yunnan Province; 28, Zhejiang Province; 29, Chongqing City; 30, Ningxia Autonomous