SELECT
*
FROM
(
SELECT
SUBA.PF_CODE AS CODE
,PREFECTURE.PF_NAME AS NAME
,ROUND(CAST(sub2 AS float)/CAST(sub1 AS float)*100,1) AS PERCENTAGE
FROM

(
SELECT
    PF_CODE
    ,SUM(AMT) AS 'sub1'
    ,SUM(CASE WHEN CATEGORY_CODE = '120' THEN AMT ELSE 0 END) AS 'sub2'
FROM
    DRINK_HABITS
WHERE
    GENDER_CODE IN ('2','3')
GROUP BY
    PF_CODE
) SUBA LEFT OUTER JOIN PREFECTURE ON (PREFECTURE.PF_CODE = SUBA.PF_CODE)
)
ORDER BY PERCENTAGE,CODE