Can't find much about the numbers of prisoners. But folks should check out the plan progressivo. (i had to use scihub to view) Most Cuban prisoners have short term stays (1-4 years). Are paid the same as civilians. Are watched and given political education by civilians who do the same work, live in the same quarters and eat the same food as the prisoners. There are lots of sports, with baseball being pretty popular. It kinda sounds closer to a summer camp with classes, paid farm work and camp counselors than what we think about prisons in the US.