Question: when did system of a down come out
[{'answer': '1994', 'provenance': [{'wikipedia_id': '28715', 'title': 'System of a Down', 'start_paragraph_id': 1, 'start_character': 77, 'end_paragraph_id': 1, 'end_character': 81, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '28715', 'title': 'System of a Down', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 249, 'bleu_score': 0.6658031069959071, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 170783035626090887}, 'section': 'Section::::Abstract.'}]}]