... In 2007, the U.S. State Department issued roughly 40,000 F-1 student visas to residents of mainland China. (Visa numbers may not correspond exactly with enrollments, but can be a useful measure.) By comparison, 46,000 visas were issued to students from South Korea that year, 34,000 to India, 22,000 to Japan, and 15,000 to Taiwan.
Five years later, visas for South Korean, Indian, Japanese, and Taiwanese students had all declined. Chinese students visas, meanwhile, quadrupled, to 189,000 in 2012, more than the total number issued to students from North America, South America, Europe, Africa, and Oceania combined. [Bold emphasis added]
More on these astonishing numbers, and the drivers behind them, in Kevin Carey's piece in The Chronicle of Higher Education.