SELECT 
    PREFECTURE.PF_CODE AS 都道府県コード, 
    PREFECTURE.PF_NAME AS 都道府県名,
    ROUND(
    CAST(HOSPITALIZATION.INP_YES AS REAL)  / 
    ( CAST(HOSPITALIZATION.INP_YES AS REAL) + CAST(HOSPITALIZATION.INP_NO AS REAL) + CAST(HOSPITALIZATION.UNIDENTIFIED AS REAL) )
    * 100
    , 1)
AS 入院率 
FROM PREFECTURE
LEFT OUTER JOIN
HOSPITALIZATION
ON PREFECTURE.PF_CODE = HOSPITALIZATION.PF_CODE
WHERE HOSPITALIZATION.UNIDENTIFIED IS NOT NULL
ORDER BY 3 DESC, 1