Question: when did burning man move to black rock city
[{'answer': '1998', 'provenance': [{'wikipedia_id': '203785', 'title': 'Burning Man', 'start_paragraph_id': 16, 'start_character': 622, 'end_paragraph_id': 16, 'end_character': 626, 'bleu_score': 1.0, 'section': 'Section::::History.:1997 to present.\n'}]}, {'provenance': [{'wikipedia_id': '203785', 'title': 'Burning Man', 'start_paragraph_id': 16, 'start_character': 0, 'end_paragraph_id': 16, 'end_character': 740, 'bleu_score': 0.9651324673660481, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4445088221114478908}, 'section': 'Section::::History.:1997 to present.\n'}]}]