Question: when did the separation of ontario hydro occur
[{'answer': 'March 31 , 1999', 'provenance': [{'wikipedia_id': '581307', 'title': 'Ontario Hydro', 'start_paragraph_id': 53, 'start_character': 3, 'end_paragraph_id': 53, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Break-up.:Stranded debt.\n'}]}, {'provenance': [{'wikipedia_id': '581307', 'title': 'Ontario Hydro', 'start_paragraph_id': 51, 'start_character': 0, 'end_paragraph_id': 51, 'end_character': 350, 'bleu_score': 0.9611463610973231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14129349721326415819}, 'section': 'Section::::Break-up.\n'}]}]