Question: when was the first warning label put on cigarettes
[{'answer': '1966', 'provenance': [{'wikipedia_id': '1233983', 'title': 'Tobacco packaging warning messages', 'start_paragraph_id': 809, 'start_character': 3, 'end_paragraph_id': 809, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::United States of America.\n'}]}, {'provenance': [{'wikipedia_id': '1233983', 'title': 'Tobacco packaging warning messages', 'start_paragraph_id': 809, 'start_character': 0, 'end_paragraph_id': 809, 'end_character': 113, 'bleu_score': 0.9021315316859231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9278060780630048715}, 'section': 'Section::::United States of America.\n'}]}]