Question: what is the national debt of the united states of america
[{'answer': '$21.3 trillion'}, {'provenance': [{'wikipedia_id': '322221', 'title': 'National debt of the United States', 'start_paragraph_id': 16, 'start_character': 0, 'end_paragraph_id': 16, 'end_character': 446, 'bleu_score': 0.565368184233309, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10948298117989081512}, 'section': 'Section::::Valuation and measurement.:Public and government accounts.\n'}]}]