Question: how many years has it been since a category 4 hit puerto rico
[{'answer': '2017', 'provenance': [{'wikipedia_id': '2588836', 'title': 'List of Category 5 Atlantic hurricanes', 'start_paragraph_id': 2, 'start_character': 54, 'end_paragraph_id': 2, 'end_character': 58, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]