拿64绿卡的老留只有54000，再加上九十年代来美国的老留，去掉去世的/离开美国的，剩下的老留可能不超过二十万。

Chinese Student Protection Act of 1992

"Over the years, the Act granted green cards to an estimated number of 54,000 Chinese nationals."

https://en.wikipedia.org/wiki/Chinese_Student_Protection_Act_of_1992#:~:text=The%2520CSPA%2520was%2520prompted%2520by,the%2520Chinese%2520Student%2520Protection%2520Act.%E2%80%9D