Question: when did six flags over mid america open
[{'answer': 'June 5 , 1971', 'provenance': [{'wikipedia_id': '447921', 'title': 'Six Flags St. Louis', 'start_paragraph_id': 5, 'start_character': 37, 'end_paragraph_id': 5, 'end_character': 50, 'bleu_score': 1.0, 'section': 'Section::::History.:Opening and operation.\n'}]}]