Question: when did the fire falls stop in yosemite
[{'answer': 'January 1968', 'provenance': [{'wikipedia_id': '3980644', 'title': 'Yosemite Firefall', 'start_paragraph_id': 2, 'start_character': 22, 'end_paragraph_id': 2, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3980644', 'title': 'Yosemite Firefall', 'start_paragraph_id': 2, 'start_character': 4, 'end_paragraph_id': 2, 'end_character': 402, 'bleu_score': 0.8748153493243531, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16468890374370762336}, 'section': 'Section::::Abstract.'}]}]