Question: when was the last time stamps went up
[{'answer': 'January 26 , 2014', 'provenance': [{'wikipedia_id': '270009', 'title': 'Postage stamps and postal history of the United States', 'start_paragraph_id': 140, 'start_character': 3, 'end_paragraph_id': 140, 'end_character': 20, 'bleu_score': 1.0, 'section': 'Section::::Modern U.S. stamps.\n'}]}, {'provenance': [{'wikipedia_id': '270009', 'title': 'Postage stamps and postal history of the United States', 'start_paragraph_id': 140, 'start_character': 0, 'end_paragraph_id': 140, 'end_character': 170, 'bleu_score': 0.929712191543383, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7021502316940770742}, 'section': 'Section::::Modern U.S. stamps.\n'}]}]