Question: when was the last time okc won a championship
[{'answer': '1979', 'provenance': [{'wikipedia_id': '18256220', 'title': 'Oklahoma City Thunder', 'start_paragraph_id': 3, 'start_character': 390, 'end_paragraph_id': 3, 'end_character': 394, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]