Question: when was the mgm grand in las vegas built
[{'answer': '1993', 'provenance': [{'wikipedia_id': '699781', 'title': 'MGM Grand Las Vegas', 'start_paragraph_id': 1, 'start_character': 383, 'end_paragraph_id': 1, 'end_character': 387, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '699781', 'title': 'MGM Grand Las Vegas', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 445, 'bleu_score': 0.903673655697073, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3268960323281079206}, 'section': 'Section::::Abstract.'}]}]