Question: when did the countries in central asia and the caucasus become independent
[{'answer': '1991', 'provenance': [{'wikipedia_id': '1577162', 'title': 'History of Central Asia', 'start_paragraph_id': 4, 'start_character': 41, 'end_paragraph_id': 4, 'end_character': 45, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1577162', 'title': 'History of Central Asia', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 256, 'bleu_score': 0.9451524926983921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3006019207416327251}, 'section': 'Section::::Abstract.'}]}]