> 15-20% of the world is estimated to have a disability. So Stanford population is high, but approximately double the average of a random global population sample.

Stanford is not a random sample of the global population. Most notably, Stanford undergraduates are young, primarily between 18-24[1]. 8.7% of people in the US from ages 18-29 have a disability [2].

[1] https://www.meetyourclass.com/stanford/student-population

[2] https://askearn.org/page/statistics-on-disability#:~:text=8....