Question: when did the black plague start and end
[{'answer': '1347 to 1351', 'provenance': [{'wikipedia_id': '4501', 'title': 'Black Death', 'start_paragraph_id': 1, 'start_character': 243, 'end_paragraph_id': 1, 'end_character': 255, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4501', 'title': 'Black Death', 'start_paragraph_id': 1, 'start_character': 61, 'end_paragraph_id': 1, 'end_character': 597, 'bleu_score': 0.746315124495684, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14965975681085985900}, 'section': 'Section::::Abstract.'}]}]