context: Pearl Jam is an American rock band, one of four key groups [1] [2] [3] (along with Alice in Chains, Nirvana and Soundgarden) of the grunge music movement, which was very popular in the first half of the 1990s. The group quickly became famous thanks to its debut album, Ten, in 1991 [4]. In the XXI century, Pearl Jam continues to release albums, despite the fact that their new works do not reach the same level of popularity that accompanied their first three albums Ten, Vs. and Vitalogy.
question: When did the Pearl Jam debut album come out?
answers.text: 1991