Question: how far is union station from ohare airport
[{'answer': '18.6 miles'}, {'provenance': [{'wikipedia_id': '14681645', 'title': "O'Hare Transfer station", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 380, 'bleu_score': 0.82742981324883, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10810995326993473140}, 'section': 'Section::::Abstract.'}]}]