Question: when was the last time yellowstone supervolcano erupted
[{'answer': '174,000 years ago', 'provenance': [{'wikipedia_id': '379647', 'title': 'Yellowstone Caldera', 'start_paragraph_id': 7, 'start_character': 379, 'end_paragraph_id': 7, 'end_character': 396, 'bleu_score': 1.0, 'section': 'Section::::Volcanism at Yellowstone.\n'}]}, {'provenance': [{'wikipedia_id': '379647', 'title': 'Yellowstone Caldera', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 1098, 'bleu_score': 0.9877670085238551, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2994833601425493882}, 'section': 'Section::::Volcanism at Yellowstone.\n'}]}]