Question: when did the b 52 bomber come out
[{'answer': '1952', 'provenance': [{'wikipedia_id': '18933037', 'title': 'Boeing B-52 Stratofortress', 'start_paragraph_id': 2, 'start_character': 259, 'end_paragraph_id': 2, 'end_character': 263, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18933037', 'title': 'Boeing B-52 Stratofortress', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 621, 'bleu_score': 0.748902789858858, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2806390374885924801}, 'section': 'Section::::Abstract.'}]}]