Question: when was the last time mt lassen erupted
[{'answer': 'May 22 , 1915', 'provenance': [{'wikipedia_id': '345248', 'title': 'Lassen Peak', 'start_paragraph_id': 39, 'start_character': 3, 'end_paragraph_id': 39, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Eruptive history.:1914–1921.\n'}]}, {'provenance': [{'wikipedia_id': '345248', 'title': 'Lassen Peak', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 345, 'bleu_score': 0.606919709680596, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3906700857530984469}, 'section': 'Section::::Abstract.'}]}]