Question: In what year was the album Clockwork Indigo released which featured both The Underachievers and American Hip Hop group Flatbush  Zombies?
Sentence (from "Clockwork Indigo EP"): Clockwork Indigo is the self-titled EP by American hip hop group Clockwork Indigo (consisting of Hip hop groups Flatbush Zombies and The Underachievers).
Relevant evidence: Yes