Question: when did the big boy burger come out
[{'answer': 'February 1937', 'provenance': [{'wikipedia_id': '1247440', 'title': 'Big Boy Restaurants', 'start_paragraph_id': 26, 'start_character': 42, 'end_paragraph_id': 26, 'end_character': 55, 'bleu_score': 1.0, 'section': 'Section::::Food.:The Big Boy hamburger.\n'}]}, {'provenance': [{'wikipedia_id': '1247440', 'title': 'Big Boy Restaurants', 'start_paragraph_id': 26, 'start_character': 0, 'end_paragraph_id': 26, 'end_character': 467, 'bleu_score': 0.9483760590755851, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9200563485129957621}, 'section': 'Section::::Food.:The Big Boy hamburger.\n'}]}]