Question: when did puerto become part of the usa
[{'answer': '1917', 'provenance': [{'wikipedia_id': '23041', 'title': 'Puerto Rico', 'start_paragraph_id': 4, 'start_character': 60, 'end_paragraph_id': 4, 'end_character': 64, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '23041', 'title': 'Puerto Rico', 'start_paragraph_id': 50, 'start_character': 0, 'end_paragraph_id': 50, 'end_character': 411, 'bleu_score': 0.8209422640716041, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14752865888229376462}, 'section': 'Section::::History.:American colony (1898–present).:U.S. citizenship and Puerto Rican citizenship.\n'}]}]