Question: when did nike become a publicly traded company
[{'answer': '1980', 'provenance': [{'wikipedia_id': '18998781', 'title': 'Nike, Inc.', 'start_paragraph_id': 8, 'start_character': 246, 'end_paragraph_id': 8, 'end_character': 250, 'bleu_score': 1.0, 'section': 'Section::::Origins and history.\n'}]}, {'provenance': [{'wikipedia_id': '18998781', 'title': 'Nike, Inc.', 'start_paragraph_id': 8, 'start_character': 0, 'end_paragraph_id': 8, 'end_character': 375, 'bleu_score': 0.970362113628587, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4791008666651902180}, 'section': 'Section::::Origins and history.\n'}]}]