Back in early 90's, I went back to school to pick up another BS, but in C.S. Because I had already coded professionally for 10 years, I helped out on the CS 101, and 201 classes. Regularly, you would have 1-2 Americans that were cheating. However, the main group that we caught over and over was the Chinese group (interestingly, only a very little bit in the Indian group ). If we pulled in individuals from these groups, they could not answer the questions or analogs to them.
It was obvious even back then that the amount of cheating that went on was enormous within the chinese group.
Now, what I find interesting, is that I am modded as a troll, even though I had out and out worked with this.