Question: when was lead paint banned in the us
[{'answer': '1971', 'provenance': [{'wikipedia_id': '23034778', 'title': 'Lead-based paint in the United States', 'start_paragraph_id': 3, 'start_character': 90, 'end_paragraph_id': 3, 'end_character': 94, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '23034778', 'title': 'Lead-based paint in the United States', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 334, 'bleu_score': 0.8700465171198001, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10219431119348429609}, 'section': 'Section::::Abstract.'}]}]