Question: when did big brown win the kentucky derby
[{'answer': '2008', 'provenance': [{'wikipedia_id': '16689920', 'title': 'Big Brown', 'start_paragraph_id': 1, 'start_character': 123, 'end_paragraph_id': 1, 'end_character': 127, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '16689920', 'title': 'Big Brown', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 286, 'bleu_score': 0.9269343237061861, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12213346943596262952}, 'section': 'Section::::Abstract.'}]}]