Question: when was the last model a ford built
[{'answer': '1931', 'provenance': [{'wikipedia_id': '6578150', 'title': 'Ford Model A (1927–31)', 'start_paragraph_id': 5, 'start_character': 464, 'end_paragraph_id': 5, 'end_character': 468, 'bleu_score': 1.0, 'section': 'Section::::Features.\n'}]}]