At bottom are some figures I first blogged about in 2004 (if you know of more recent data, please tell me). They indicate that already by the late 1990s there were more Asian students staying at home to do their graduate work than coming to the US. Yet, as the 2007 numbers show, Asia is our largest source of applicants. Related posts.
2007:
china 158
usa 75
india 19
nepal 2
sri lanka 2
taiwan 3
korea 4
indian 3
new zealand 1
germany 1
colombia 1
egypt 2
bangladesh 1
japan 2
iraq 1
pakistani 1
eritrea 1
More up to date numbers here:
...Overall, the U.S. share of world S&E PhDs will fall to about 15% by 2010. Within the US, moreover, international students have come to earn an increasing proportion of S&E PhDs. In 1966, US-born males accounted for 71% of science and engineering PhDs awarded; 6% were awarded to US-born females; and 23% were awarded to the foreign-born. In 2000, 36% of S&E PhDs went to U.S.-born males, 25% to U.S.-born females and 39% to the foreign-born. 8 Looking among the S&E fields, in 2002, international students received 19.5% of all doctorates awarded in the social and behavioral sciences, 18.0% in the life sciences, 35.4% in the physical sciences, and 58.7% in engineering.