Question: when did mcdonald's big mac come out
[{'answer': '1967', 'provenance': [{'wikipedia_id': '299395', 'title': 'Big Mac', 'start_paragraph_id': 1, 'start_character': 156, 'end_paragraph_id': 1, 'end_character': 160, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '299395', 'title': 'Big Mac', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 229, 'bleu_score': 0.907026096796234, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15584713469890063501}, 'section': 'Section::::Abstract.'}]}]