Question: how many no hitters in world series history
[{'answer': 'two', 'provenance': [{'wikipedia_id': '329902', 'title': 'No-hitter', 'start_paragraph_id': 1, 'start_character': 550, 'end_paragraph_id': 1, 'end_character': 553, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '329902', 'title': 'No-hitter', 'start_paragraph_id': 36, 'start_character': 0, 'end_paragraph_id': 36, 'end_character': 890, 'bleu_score': 0.9441381734938701, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16272957735658698506}, 'section': 'Section::::Major League Baseball no-hitters.:Opening Day, title-clinching, and postseason no-hitters.\n'}]}]