Question: when did they start putting filters on cigarettes
[{'answer': '1935', 'provenance': [{'wikipedia_id': '4576717', 'title': 'Cigarette filter', 'start_paragraph_id': 7, 'start_character': 5, 'end_paragraph_id': 7, 'end_character': 9, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '4576717', 'title': 'Cigarette filter', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 528, 'bleu_score': 0.9430699958503841, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17548708738824395533}, 'section': 'Section::::History.\n'}]}]