Question: when did the battle of bosworth begin and end
[{'answer': '22 August 1485', 'provenance': [{'wikipedia_id': '3793', 'title': 'Battle of Bosworth Field', 'start_paragraph_id': 1, 'start_character': 245, 'end_paragraph_id': 1, 'end_character': 259, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]