Question: who did mexico win its independence from in 1821
[{'answer': 'Spain', 'provenance': [{'wikipedia_id': '785587', 'title': 'Mexican War of Independence', 'start_paragraph_id': 1, 'start_character': 180, 'end_paragraph_id': 1, 'end_character': 185, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]