Question: when did team spirit win the grand national
[{'answer': '21 March 1964', 'provenance': [{'wikipedia_id': '33725073', 'title': '1964 Grand National', 'start_paragraph_id': 1, 'start_character': 145, 'end_paragraph_id': 1, 'end_character': 158, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]