Question: when was the last time lake powell was full
[{'answer': 'July 14 , 1983', 'provenance': [{'wikipedia_id': '357078', 'title': 'Lake Powell', 'start_paragraph_id': 9, 'start_character': 418, 'end_paragraph_id': 9, 'end_character': 432, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '357078', 'title': 'Lake Powell', 'start_paragraph_id': 9, 'start_character': 0, 'end_paragraph_id': 9, 'end_character': 606, 'bleu_score': 0.7726509326688521, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 588034064836520907}, 'section': 'Section::::History.\n'}]}]