Question: how many roller coasters are there at busch gardens williamsburg
[{'answer': '8', 'provenance': [{'wikipedia_id': '2790258', 'title': 'Busch Gardens Williamsburg', 'start_paragraph_id': 2, 'start_character': 287, 'end_paragraph_id': 2, 'end_character': 288, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]