Question: when did mt st helen's last erupt
[{'answer': '2008', 'provenance': [{'wikipedia_id': '673671', 'title': '1980 eruption of Mount St. Helens', 'start_paragraph_id': 72, 'start_character': 254, 'end_paragraph_id': 72, 'end_character': 258, 'bleu_score': 1.0, 'section': 'Section::::Later eruptions.\n'}]}, {'provenance': [{'wikipedia_id': '673671', 'title': '1980 eruption of Mount St. Helens', 'start_paragraph_id': 72, 'start_character': 0, 'end_paragraph_id': 72, 'end_character': 258, 'bleu_score': 0.8783650674919871, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14199946552048139598}, 'section': 'Section::::Later eruptions.\n'}]}]