Question: when was the last time the us added a state
[{'answer': '1959', 'provenance': [{'wikipedia_id': '6174697', 'title': 'Territorial evolution of the United States', 'start_paragraph_id': 5, 'start_character': 672, 'end_paragraph_id': 5, 'end_character': 676, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6174697', 'title': 'Territorial evolution of the United States', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 676, 'bleu_score': 0.6678141273422741, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10150051960336625730}, 'section': 'Section::::Abstract.'}]}]