Question: who did el salvador get their independence from
[{'answer': 'Federal Republic of Central America', 'provenance': [{'wikipedia_id': '53081', 'title': 'History of El Salvador', 'start_paragraph_id': 1, 'start_character': 402, 'end_paragraph_id': 1, 'end_character': 437, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '53081', 'title': 'History of El Salvador', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 665, 'bleu_score': 0.9486604584788991, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6146007273796194849}, 'section': 'Section::::Abstract.'}]}]