Question: when did rome go from republic to empire
[{'answer': '27 BC', 'provenance': [{'wikipedia_id': '25816', 'title': 'Roman Republic', 'start_paragraph_id': 1, 'start_character': 164, 'end_paragraph_id': 1, 'end_character': 169, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '25816', 'title': 'Roman Republic', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 355, 'bleu_score': 0.757233281652757, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11701862387022752650}, 'section': 'Section::::Abstract.'}]}]