Question: who won the us open last year 2017
[{'answer': 'Brooks Koepka', 'provenance': [{'wikipedia_id': '50875497', 'title': '2017 U.S. Open (golf)', 'start_paragraph_id': 1, 'start_character': 131, 'end_paragraph_id': 1, 'end_character': 144, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '50875497', 'title': '2017 U.S. Open (golf)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 355, 'bleu_score': 0.8567716464560671, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2910092942318044878}, 'section': 'Section::::Abstract.'}]}]