Question: when did wendy's release the vanilla frosty
[{'answer': 'August 2006', 'provenance': [{'wikipedia_id': '1251896', 'title': 'Frosty (frozen dairy dessert)', 'start_paragraph_id': 1, 'start_character': 396, 'end_paragraph_id': 1, 'end_character': 407, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1251896', 'title': 'Frosty (frozen dairy dessert)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 473, 'bleu_score': 0.9731482306711111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11212522104709108026}, 'section': 'Section::::Abstract.'}]}]