Given the task definition and input, reply with output. Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Rosemary's Billygoat is an American heavy metal/hard rock band formed in Los Angeles ' South Bay in 1991, consisting of singer Mike Odd, guitarist Neal Gargantua, bassist Pat Trick and drummer Paul Bearer.
The year that Rosemary's Billygoat was created was?