Question: when is the last time the kansas city chiefs went to the superbowl
[{'answer': '1969', 'provenance': [{'wikipedia_id': '20297793', 'title': 'Kansas City Chiefs', 'start_paragraph_id': 2, 'start_character': 64, 'end_paragraph_id': 2, 'end_character': 68, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]