Passage: The infamous penal colonies, including Devil's Island, were gradually phased out and then formally closed in 1951. At first, only those freed prisoners who could raise the fare for their return passage to France were able to go home, so French Guiana was haunted after the official closing of the prisons by numerous freed convicts leading an aimless existence in the colony.

Question: In what year were the penal colonies officially closed?
1951