Question: what is the population of the detroit metro area
[{'answer': '3,734,090', 'provenance': [{'wikipedia_id': '490908', 'title': 'Metro Detroit', 'start_paragraph_id': 3, 'start_character': 145, 'end_paragraph_id': 3, 'end_character': 154, 'bleu_score': 1.0, 'section': 'Section::::Definitions.\n'}]}]