Question: what was the average life expectancy in the roman empire
[{'answer': '25', 'provenance': [{'wikipedia_id': '27766105', 'title': 'Demography of the Roman Empire', 'start_paragraph_id': 8, 'start_character': 150, 'end_paragraph_id': 8, 'end_character': 152, 'bleu_score': 1.0, 'section': 'Section::::Mortality.\n'}]}, {'answer': 'late - 50s'}, {'provenance': [{'wikipedia_id': '27766105', 'title': 'Demography of the Roman Empire', 'start_paragraph_id': 8, 'start_character': 0, 'end_paragraph_id': 8, 'end_character': 975, 'bleu_score': 0.9188746262580231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7916896416357453818}, 'section': 'Section::::Mortality.\n'}]}]