Question: when did the android operating system come out
[{'answer': 'September 23 , 2008', 'provenance': [{'wikipedia_id': '12610483', 'title': 'Android (operating system)', 'start_paragraph_id': 9, 'start_character': 884, 'end_paragraph_id': 9, 'end_character': 903, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]