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住在加拿大马尼托巴省的冰岛后裔居民，患季节性情感障碍的人数仅是非冰岛后裔加拿大人的一半左右。
And among Canadians of Icelandic descent living in the Canadian province Manitoba, the prevalence of SAD is approximately half that of non-Icelandic Canadians living in the same place.