Question: when did the last navajo code talker die
[{'answer': 'June 4 , 2014', 'provenance': [{'wikipedia_id': '42968845', 'title': 'Chester Nez', 'start_paragraph_id': 12, 'start_character': 12, 'end_paragraph_id': 12, 'end_character': 25, 'bleu_score': 1.0, 'section': 'Section::::Death.\n'}]}, {'provenance': [{'wikipedia_id': '42968845', 'title': 'Chester Nez', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 190, 'bleu_score': 0.943604326170661, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16976063390277656265}, 'section': 'Section::::Abstract.'}]}]