Question: when did payne stewart won the us open
[{'answer': '1991', 'provenance': [{'wikipedia_id': '349744', 'title': 'Payne Stewart', 'start_paragraph_id': 2, 'start_character': 78, 'end_paragraph_id': 2, 'end_character': 82, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': '1999', 'provenance': [{'wikipedia_id': '349744', 'title': 'Payne Stewart', 'start_paragraph_id': 1, 'start_character': 54, 'end_paragraph_id': 1, 'end_character': 58, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]