Question: when does the thunderbird open at holiday world
[{'answer': '2015', 'provenance': [{'wikipedia_id': '43388951', 'title': 'Thunderbird (Holiday World)', 'start_paragraph_id': 1, 'start_character': 156, 'end_paragraph_id': 1, 'end_character': 160, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '43388951', 'title': 'Thunderbird (Holiday World)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 236, 'bleu_score': 0.9493253852526031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7800153754640438117}, 'section': 'Section::::Abstract.'}]}]