The Environment of a Maximum Security Prison

The prison is one of the fifth oldest maximum security prisons in the country. The population was designed for about 800 inmates, and when I left we had 1,250 plus inmates. When you say, and it's supposed to house 800, but you guys had over 1,200 inmates, is that typical for prisons? Or is it like, why can you just fit 400 more people than it's designed to fit? It's not designed to fit that.