Question: when did they start putting iodine in salt
[{'answer': '1924', 'provenance': [{'wikipedia_id': '1232890', 'title': 'Iodised salt', 'start_paragraph_id': 37, 'start_character': 200, 'end_paragraph_id': 37, 'end_character': 204, 'bleu_score': 1.0, 'section': 'Section::::In public health initiatives.:United States.\n'}]}, {'provenance': [{'wikipedia_id': '1232890', 'title': 'Iodised salt', 'start_paragraph_id': 37, 'start_character': 0, 'end_paragraph_id': 37, 'end_character': 337, 'bleu_score': 0.5368653734766781, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17420969657930190424}, 'section': 'Section::::In public health initiatives.:United States.\n'}]}]