This I know. My question is, has it always been so, or are Americans decreasing and internationals increasing? I know international representation has generall

This I know. My question is, has it always been so, or are Americans decreasing and internationals increasing? I know international representation has generally increased in academics due to their cash cow status with higher tuition rates and most restricted employment options… but I don’t know if this applies specifically to PhD and grad just the same If so, then the bigger story here is, why is America producing fewer and fewer high academic achievers (PhD, grad, high school reading level, all the way down to lower ed)