Question: when was the last time tigers won world series
[{'answer': '1984', 'provenance': [{'wikipedia_id': '8579', 'title': 'Detroit Tigers', 'start_paragraph_id': 1, 'start_character': 597, 'end_paragraph_id': 1, 'end_character': 601, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]