Question: when's the last time calgary stampeders won the grey cup
[{'answer': '2014', 'provenance': [{'wikipedia_id': '254169', 'title': 'Calgary Stampeders', 'start_paragraph_id': 24, 'start_character': 17, 'end_paragraph_id': 24, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::Franchise history.:2008–2015: Hufnagel years.\n'}]}, {'provenance': [{'wikipedia_id': '254169', 'title': 'Calgary Stampeders', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 395, 'bleu_score': 0.786943131109035, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6001690867181397153}, 'section': 'Section::::Abstract.'}]}]