Question: when did cash cab go off the air
[{'answer': 'April 18 , 2012', 'provenance': [{'wikipedia_id': '19920744', 'title': 'Cash Cab (American game show)', 'start_paragraph_id': 8, 'start_character': 3, 'end_paragraph_id': 8, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Broadcast history.\n'}]}]