Question: when was the last time unc was ranked in football
[{'answer': '2015', 'provenance': [{'wikipedia_id': '7957912', 'title': 'North Carolina Tar Heels football', 'start_paragraph_id': 61, 'start_character': 3, 'end_paragraph_id': 61, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::History.:Larry Fedora era (2012–2018).\n'}]}, {'provenance': [{'wikipedia_id': '7957912', 'title': 'North Carolina Tar Heels football', 'start_paragraph_id': 61, 'start_character': 0, 'end_paragraph_id': 61, 'end_character': 745, 'bleu_score': 0.836169219438587, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 191273180891558808}, 'section': 'Section::::History.:Larry Fedora era (2012–2018).\n'}]}]