Question: when did iphone 6 come out in usa
[{'answer': 'September 19 , 2014', 'provenance': [{'wikipedia_id': '42259842', 'title': 'IPhone 6', 'start_paragraph_id': 7, 'start_character': 179, 'end_paragraph_id': 7, 'end_character': 198, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '42259842', 'title': 'IPhone 6', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 591, 'bleu_score': 0.7344109386051341, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8243810893389563633}, 'section': 'Section::::Abstract.'}]}]