【Google データポータル】GoogleAnalyticsの地域(都道府県)から地方別表示したい場合

Google データポータルで、GoogleAnalyticsのレポートを作成する際に地域ディメンションを都道府県単位ではなく、地方エリアごとのグループにまとめてグラフを作りたい場合は、データソースのフィールドからCASEの関数で下記のコードを追加します。

CASE 
    WHEN 地域 IN ("Hokkaido") THEN "北海道地方"
    WHEN 地域 IN ("Aomori","Iwate","Miyagi","Akita","Yamagata","Fukushima") THEN "東北地方"
    WHEN 地域 IN ("Ibaraki","Tochigi","Gunma","Saitama","Chiba","Tokyo","Kanagawa") THEN "関東地方"
    WHEN 地域 IN ("Niigata","Toyama","Ishikawa","Fukui","Yamanashi","Nagano","Gifu","Shizuoka","Aichi") THEN "中部地方"
    WHEN 地域 IN ("Mie","Shiga","Kyoto","Osaka","Hyogo","Nara","Wakayama") THEN "関西地方"
    WHEN 地域 IN ("Tottori","Shimane","Okayama","Hiroshima","Yamaguchi") THEN "中国地方"
    WHEN 地域 IN ("Tokushima","Kagawa","Ehime","Kochi") THEN "四国地方"
    WHEN 地域 IN ("Fukuoka","Saga","Nagasaki","Kumamoto","Oita","Miyazaki","Kagoshima","Okinawa") THEN "九州地方"
    ELSE "不明" 
END	

※手動で記載していますので、間違っていたらすみません