Question: what percentage of the us population is east of the mississippi
[{'answer': '58.28 %', 'provenance': [{'wikipedia_id': '509486', 'title': 'Eastern United States', 'start_paragraph_id': 2, 'start_character': 208, 'end_paragraph_id': 2, 'end_character': 217, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '509486', 'title': 'Eastern United States', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 281, 'bleu_score': 0.9569637990759251, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11650727724849730955}, 'section': 'Section::::Abstract.'}]}]