Question: when did leeds united win the fa cup
[{'answer': '6 May 1972', 'provenance': [{'wikipedia_id': '7382128', 'title': '1972 FA Cup Final', 'start_paragraph_id': 1, 'start_character': 36, 'end_paragraph_id': 1, 'end_character': 46, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]