Original: The unexpected success of "Smells Like Teen Spirit" in late 1991 propelled Nevermind to the top of the charts at the start of 1992, an event often marked as the point where alternative rock entered the mainstream. "Smells Like Teen Spirit" was Nirvana's first and biggest hit, reaching number six on the Billboard Hot 100 and placing high on music industry charts all around the world in 1991 and 1992.
Simplified: Smells Like Teen Spirit was released in 1991.