Question: when did the oklahoma city thunder become a team
[{'answer': '1967', 'provenance': [{'wikipedia_id': '18256220', 'title': 'Oklahoma City Thunder', 'start_paragraph_id': 5, 'start_character': 11, 'end_paragraph_id': 5, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Franchise history.\n'}]}]