Question: when did lead singer of linkin park die
[{'answer': 'July 20 , 2017', 'provenance': [{'wikipedia_id': '142809', 'title': 'Chester Bennington', 'start_paragraph_id': 33, 'start_character': 135, 'end_paragraph_id': 33, 'end_character': 149, 'bleu_score': 1.0, 'section': 'Section::::Death.\n'}]}, {'provenance': [{'wikipedia_id': '142809', 'title': 'Chester Bennington', 'start_paragraph_id': 2, 'start_character': 813, 'end_paragraph_id': 2, 'end_character': 948, 'bleu_score': 0.812034170285978, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4635645490308940797}, 'section': 'Section::::Abstract.'}]}]