Question: when was mt. rushmore built and finished
[{'answer': '1927 to 1941', 'provenance': [{'wikipedia_id': '185973', 'title': 'Mount Rushmore', 'start_paragraph_id': 1, 'start_character': 249, 'end_paragraph_id': 1, 'end_character': 261, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]