Question: when did ethanol start being added to gasoline
[{'answer': 'the late 1970s', 'provenance': [{'wikipedia_id': '5029525', 'title': 'Ethanol fuel in the United States', 'start_paragraph_id': 12, 'start_character': 90, 'end_paragraph_id': 12, 'end_character': 104, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '5029525', 'title': 'Ethanol fuel in the United States', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 821, 'bleu_score': 0.985764216565234, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5136315925422590763}, 'section': 'Section::::History.\n'}]}]