Question: when was the last western roman emperor overthrown
[{'answer': '31 October AD 475'}, {'provenance': [{'wikipedia_id': '25789', 'title': 'Romulus Augustulus', 'start_paragraph_id': 1, 'start_character': 61, 'end_paragraph_id': 1, 'end_character': 539, 'bleu_score': 0.5144410718412661, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6417110071648641557}, 'section': 'Section::::Abstract.'}]}]