Question: when was the rank of corporal established in the marine corps
[{'answer': '1942', 'provenance': [{'wikipedia_id': '234095', 'title': 'Corporal', 'start_paragraph_id': 128, 'start_character': 94, 'end_paragraph_id': 128, 'end_character': 98, 'bleu_score': 1.0, 'section': 'Section::::United States.:United States Marine Corps.\n'}]}, {'provenance': [{'wikipedia_id': '234095', 'title': 'Corporal', 'start_paragraph_id': 128, 'start_character': 0, 'end_paragraph_id': 128, 'end_character': 755, 'bleu_score': 0.9643025203494101, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16227341120605309194}, 'section': 'Section::::United States.:United States Marine Corps.\n'}]}]