Question: who won the grand national last year 2017
[{'answer': 'One For Arthur', 'provenance': [{'wikipedia_id': '53072911', 'title': '2017 Grand National', 'start_paragraph_id': 3, 'start_character': 20, 'end_paragraph_id': 3, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '53072911', 'title': '2017 Grand National', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 237, 'bleu_score': 0.8989354241697111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14559724024066199571}, 'section': 'Section::::Abstract.'}]}]