Question: when did the yankees win their last world series
[{'answer': '2009', 'provenance': [{'wikipedia_id': '4848143', 'title': 'New York Yankees', 'start_paragraph_id': 2, 'start_character': 472, 'end_paragraph_id': 2, 'end_character': 476, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]