Question: when was the last time minnesota vikings was in the super bowl
[{'answer': 'XI', 'provenance': [{'wikipedia_id': '20134', 'title': 'Minnesota Vikings', 'start_paragraph_id': 7, 'start_character': 549, 'end_paragraph_id': 7, 'end_character': 551, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': '1969', 'provenance': [{'wikipedia_id': '20134', 'title': 'Minnesota Vikings', 'start_paragraph_id': 2, 'start_character': 172, 'end_paragraph_id': 2, 'end_character': 176, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '20134', 'title': 'Minnesota Vikings', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 746, 'bleu_score': 0.9678713199044161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8514473309705399880}, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '20134', 'title': 'Minnesota Vikings', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8514473309705399880}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '20134', 'title': 'Minnesota Vikings', 'section': 'Section::::Abstract.', 'start_paragraph_id': 2, 'end_paragraph_id': 2, 'meta': {'evidence_span': ["In 1969, their dominant defense led to the Vikings' league championship, the last NFL championship prior to the merger of the NFL with the AFL.", "In 1969, their dominant defense led to the Vikings' league championship, the last NFL championship prior to the merger of the NFL with the AFL.", "During the 1960s, the Vikings' record was typical for an expansion franchise, but improved over the course of the decade, resulting in a Central Division title in 1968. In 1969, their dominant defense led to the Vikings' league championship, the last NFL championship prior to the merger of the NFL with the AFL."]}}]}]