I am ignoring where people apply, just adjusting for % of population and % of high school graduates. There are a lot of ways to play with the numbers but that seemed like a good first approximation.
Also, international students are 8.70% of undergrads at Stanford, so they can't really change the stats that much.
I would guess Asian students are a majority among international applicants to Stanford. If we then looked at high school 'graduation' worldwide as the baseline, that's probably an underrepresentation.