A newly released report shows that 42 people have broken into prisons in England and Wales in the last five years.

According to reports, prostitutes and drug dealers are breaking into prisons in order to sell sex and drugs to inmates. The Guardian said that drugs are actually cheaper inside prison than on the street, because there is such an abundance of them within prison walls. Others say some of the break-ins may occur because prisoners become institutionalized and are not comfortable in the free world.

The released report said that the all but one of the break-ins happened in open prisons, in which prisoners are allowed to leave prison grounds, but must be there for daily roll-call.

Gaining access is often done with the use of ladders, or climbing trees or walls. Authorities have cut down trees and added fencing and other security measures at many of the open prisons. They say that while people have been able to break in, inmates are confined to their cells at night, when the break-ins occur.