Question: what is the population of greater las vegas
[{'answer': '2,227,053', 'provenance': [{'wikipedia_id': '665172', 'title': 'Las Vegas Valley', 'start_paragraph_id': 3, 'start_character': 106, 'end_paragraph_id': 3, 'end_character': 115, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]