Question: when was the last time mount saint helens exploded
[{'answer': 'May 18 , 1980', 'provenance': [{'wikipedia_id': '673671', 'title': '1980 eruption of Mount St. Helens', 'start_paragraph_id': 62, 'start_character': 386, 'end_paragraph_id': 62, 'end_character': 399, 'bleu_score': 1.0, 'section': 'Section::::Aftermath.:Direct results.:Disputed death toll.\n'}]}, {'provenance': [{'wikipedia_id': '673671', 'title': '1980 eruption of Mount St. Helens', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 643, 'bleu_score': 0.9457574291320461, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14850500819655953952}, 'section': 'Section::::Abstract.'}]}]