Question: when was the last air force one built
[{'answer': '1990', 'provenance': [{'wikipedia_id': '148475', 'title': 'Air Force One', 'start_paragraph_id': 4, 'start_character': 146, 'end_paragraph_id': 4, 'end_character': 150, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '148475', 'title': 'Air Force One', 'start_paragraph_id': 32, 'start_character': 0, 'end_paragraph_id': 32, 'end_character': 842, 'bleu_score': 0.917031751151656, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3756466243973722206}, 'section': 'Section::::History.:Boeing VC-25A.\n'}]}]