Question: when was the national minimum wage last raised
[{'answer': 'July 2009', 'provenance': [{'wikipedia_id': '11477230', 'title': 'Minimum wage in the United States', 'start_paragraph_id': 14, 'start_character': 97, 'end_paragraph_id': 14, 'end_character': 106, 'bleu_score': 1.0, 'section': 'Section::::Legislation.\n'}]}, {'provenance': [{'wikipedia_id': '11477230', 'title': 'Minimum wage in the United States', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 840, 'bleu_score': 0.9868845362499331, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1206616863054394000}, 'section': 'Section::::Legislation.\n'}]}]