Question: when was the last time the uk had a white christmas
[{'answer': '2009', 'provenance': [{'wikipedia_id': '176827', 'title': 'White Christmas (weather)', 'start_paragraph_id': 16, 'start_character': 10, 'end_paragraph_id': 16, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::White Christmases in the United Kingdom.\n'}]}, {'provenance': [{'wikipedia_id': '176827', 'title': 'White Christmas (weather)', 'start_paragraph_id': 16, 'start_character': 0, 'end_paragraph_id': 16, 'end_character': 374, 'bleu_score': 0.968982777549629, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7418098407360337520}, 'section': 'Section::::White Christmases in the United Kingdom.\n'}]}]