Question: what percentage of europe's population died of the plague
[{'answer': '30 -- 60 %'}, {'provenance': [{'wikipedia_id': '4501', 'title': 'Black Death', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 350, 'bleu_score': 0.8223392880143131, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6118844124224726051}, 'section': 'Section::::Abstract.'}]}]