Question: when was the last time the national minimum wage was raised
[{'answer': 'July 24 , 2009', 'provenance': [{'wikipedia_id': '11477230', 'title': 'Minimum wage in the United States', 'start_paragraph_id': 1, 'start_character': 214, 'end_paragraph_id': 1, 'end_character': 228, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '11477230', 'title': 'Minimum wage in the United States', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 571, 'bleu_score': 0.7311384796225221, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6179472790375125641}, 'section': 'Section::::Abstract.'}]}]