Question: when did the great basin became a national park
[{'answer': 'October 27 , 1986', 'provenance': [{'wikipedia_id': '215927', 'title': 'Great Basin National Park', 'start_paragraph_id': 4, 'start_character': 166, 'end_paragraph_id': 4, 'end_character': 183, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]