Question: when was billy don be a hero released
[{'answer': '1974', 'provenance': [{'wikipedia_id': '2622356', 'title': "Billy Don't Be a Hero", 'start_paragraph_id': 1, 'start_character': 29, 'end_paragraph_id': 1, 'end_character': 33, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2622356', 'title': "Billy Don't Be a Hero", 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 590, 'bleu_score': 0.8621533585446891, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10841121933314875716}, 'section': 'Section::::Abstract.'}]}]