Question: what is the percentage of o2 in air
[{'answer': '20.95 %', 'provenance': [{'wikipedia_id': '202898', 'title': 'Atmosphere of Earth', 'start_paragraph_id': 2, 'start_character': 45, 'end_paragraph_id': 2, 'end_character': 58, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '202898', 'title': 'Atmosphere of Earth', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 355, 'bleu_score': 0.7160582126571761, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15537475029802492255}, 'section': 'Section::::Abstract.'}]}]