Question: when did canada withdraw from the kyoto protocol
[{'answer': 'December 2011', 'provenance': [{'wikipedia_id': '16169156', 'title': 'Canada and the Kyoto Protocol', 'start_paragraph_id': 6, 'start_character': 3, 'end_paragraph_id': 6, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '16169156', 'title': 'Canada and the Kyoto Protocol', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 486, 'bleu_score': 0.9304844600065421, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 840517475347204823}, 'section': 'Section::::Abstract.'}]}]