Question: when was ar 15 made available to the public
[{'answer': '1964', 'provenance': [{'wikipedia_id': '94860', 'title': 'Colt AR-15', 'start_paragraph_id': 3, 'start_character': 332, 'end_paragraph_id': 3, 'end_character': 336, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '94860', 'title': 'Colt AR-15', 'start_paragraph_id': 3, 'start_character': 244, 'end_paragraph_id': 3, 'end_character': 633, 'bleu_score': 0.551741523933236, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11655206494021169402}, 'section': 'Section::::History.\n'}]}]