Question: when was the last time cleveland browns won a championship
[{'answer': '1989', 'provenance': [{'wikipedia_id': '6576', 'title': 'Cleveland Browns', 'start_paragraph_id': 61, 'start_character': 113, 'end_paragraph_id': 61, 'end_character': 117, 'bleu_score': 1.0, 'section': 'Section::::Rivalries.:Other rivalries.:Denver Broncos.\n'}]}]