Question: when did puerto rico gain their independence from spain
[{'answer': '1897', 'provenance': [{'wikipedia_id': '840701', 'title': 'Independence movement in Puerto Rico', 'start_paragraph_id': 11, 'start_character': 378, 'end_paragraph_id': 11, 'end_character': 382, 'bleu_score': 1.0, 'section': 'Section::::Seeking independence from Spain.:Puerto Ricans revolt.\n'}]}, {'provenance': [{'wikipedia_id': '840701', 'title': 'Independence movement in Puerto Rico', 'start_paragraph_id': 21, 'start_character': 0, 'end_paragraph_id': 21, 'end_character': 269, 'bleu_score': 0.953991849837532, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7381785048481574892}, 'section': 'Section::::Seeking independence from Spain.:Spanish Charter of Autonomy.\n'}]}]