Question: when did the eagles last win the superbowl
[{'answer': 'Super Bowl XX', 'provenance': [{'wikipedia_id': '23339', 'title': 'Philadelphia Eagles', 'start_paragraph_id': 55, 'start_character': 966, 'end_paragraph_id': 55, 'end_character': 979, 'bleu_score': 1.0, 'section': 'Section::::Franchise history.:Ryan and Kotite era (1986–1994).\n'}]}]