Question: when did yankees and dodgers last play in world series
[{'answer': '1981 World Series', 'provenance': [{'wikipedia_id': '6641267', 'title': 'Dodgers–Yankees rivalry', 'start_paragraph_id': 37, 'start_character': 76, 'end_paragraph_id': 37, 'end_character': 93, 'bleu_score': 1.0, 'section': 'Section::::Rivalry in the 21st Century.\n'}]}]