Question: when was the first time mount etna erupted
[{'answer': 'about 500,000 years ago', 'provenance': [{'wikipedia_id': '169351', 'title': 'Mount Etna', 'start_paragraph_id': 12, 'start_character': 43, 'end_paragraph_id': 12, 'end_character': 66, 'bleu_score': 1.0, 'section': 'Section::::History of volcanic eruptions.:Geological history.\n'}]}, {'provenance': [{'wikipedia_id': '169351', 'title': 'Mount Etna', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 592, 'bleu_score': 0.9373359309621411, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1077745164038459841}, 'section': 'Section::::History of volcanic eruptions.:Geological history.\n'}]}]