Question: when did coke try to change their formula
[{'answer': 'April 1985', 'provenance': [{'wikipedia_id': '355129', 'title': 'New Coke', 'start_paragraph_id': 1, 'start_character': 82, 'end_paragraph_id': 1, 'end_character': 92, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '355129', 'title': 'New Coke', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 150, 'bleu_score': 0.518550719665216, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9984917324900738585}, 'section': 'Section::::Abstract.'}]}]