Question: when did the riders win the grey cup
[{'answer': '1966', 'provenance': [{'wikipedia_id': '254166', 'title': 'Saskatchewan Roughriders', 'start_paragraph_id': 23, 'start_character': 403, 'end_paragraph_id': 23, 'end_character': 407, 'bleu_score': 1.0, 'section': 'Section::::Franchise history.:The Ken Preston Era (1958–1978).\n'}]}, {'answer': '1989', 'provenance': [{'wikipedia_id': '254166', 'title': 'Saskatchewan Roughriders', 'start_paragraph_id': 38, 'start_character': 11, 'end_paragraph_id': 38, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Franchise history.:Kent Austin era (1987–1993).\n'}]}, {'answer': '2007', 'provenance': [{'wikipedia_id': '254166', 'title': 'Saskatchewan Roughriders', 'start_paragraph_id': 49, 'start_character': 45, 'end_paragraph_id': 49, 'end_character': 49, 'bleu_score': 1.0, 'section': 'Section::::Franchise history.:Roy Shivers and Danny Barrett Era (1999–2006).\n'}]}, {'answer': '2013', 'provenance': [{'wikipedia_id': '254166', 'title': 'Saskatchewan Roughriders', 'start_paragraph_id': 59, 'start_character': 11, 'end_paragraph_id': 59, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Franchise history.:Corey Chamblin era (2012–2015).\n'}]}]