I just got done with the TRB meeting in Washington DC. I saw my old friends from Univ. of Maryland transportation engineering program. Many of whom are still there after 7 years! I learned a lot there and I was one of only 2 Americans my first year. By contrast my mother was in Grad school in Physics (University of Chicago) in the 60s. At that time 90 percent of the students were from the US. That got the demographer in me thinking.
Ever wonder what life was like in grad school in the USA before massive Gov. funding Post WWII. What people study be race, gender, and citizenship status. When did all the international students show up. This page has some nice data with a short explanation.