Question: when did the bonus army march on washington
[{'answer': 'summer of 1932'}, {'provenance': [{'wikipedia_id': '399959', 'title': 'Bonus Army', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 491, 'bleu_score': 0.8641317431470491, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9418456384132819780}, 'section': 'Section::::Abstract.'}]}]