Question: how many nfl teams has st louis had
[{'answer': 'four', 'provenance': [{'wikipedia_id': '21564794', 'title': 'Sports in St. Louis', 'start_paragraph_id': 10, 'start_character': 31, 'end_paragraph_id': 10, 'end_character': 35, 'bleu_score': 1.0, 'section': 'Section::::Football.\n'}]}, {'provenance': [{'wikipedia_id': '21564794', 'title': 'Sports in St. Louis', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7778589168014197197}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '21564794', 'title': 'Sports in St. Louis', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 77, 'bleu_score': 0.850733133512352, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7778589168014197197}, 'section': 'Section::::Football.\n'}]}, {'provenance': [{'wikipedia_id': '21564794', 'title': 'Sports in St. Louis', 'section': 'Section::::Football.\n', 'start_paragraph_id': 10, 'end_paragraph_id': 10, 'meta': {'evidence_span': ['St. Louis has been the home of four National Football League (NFL) franchises', 'St. Louis has been the home of four National Football League (NFL) franchises.', 'St. Louis has been the home of four National Football League (NFL) franchises.']}}]}]