Question: when was the last time cowboys won superbowl
[{'answer': '1995', 'provenance': [{'wikipedia_id': '8121', 'title': 'Dallas Cowboys', 'start_paragraph_id': 24, 'start_character': 22, 'end_paragraph_id': 24, 'end_character': 26, 'bleu_score': 1.0, 'section': 'Section::::History.:1990s.\n'}]}]