Question: when did they start putting fluoride in water
[{'answer': '1945', 'provenance': [{'wikipedia_id': '763637', 'title': 'Water fluoridation', 'start_paragraph_id': 8, 'start_character': 103, 'end_paragraph_id': 8, 'end_character': 107, 'bleu_score': 1.0, 'section': 'Section::::Goal.\n'}]}, {'provenance': [{'wikipedia_id': '763637', 'title': 'Water fluoridation', 'start_paragraph_id': 57, 'start_character': 0, 'end_paragraph_id': 57, 'end_character': 445, 'bleu_score': 0.860927925537954, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18399206247454405042}, 'section': 'Section::::History.\n'}]}]