So, the statistic is counting people who were educated elsewhere and then moved to the US afterward. Essentially letting the US take credit for other countries' educational programs.
I think if we just counted the average education level of people who grew up in the US it would be much lower.
The US attracts educated people from all over the world, but it does not do much to educate the majority of its own people.
Canada's immigration system works with points and education is worth a lot.
While statcan doesn't provide information on tuition, the immigration data shows that 66 000 or the 104 000 male immigrants were in the "economic" category in 2015.
I think if we just counted the average education level of people who grew up in the US it would be much lower.
The US attracts educated people from all over the world, but it does not do much to educate the majority of its own people.