SELECT
    HP.PF_CODE AS 都道府県コード
    , PF.PF_NAME AS 都道府県名
    , ROUND( 
        -- 計算項目がINTEGER型なのでCAST関数でREAL型に変換して計算しています
        CAST(HP.INP_YES AS REAL) /
        CAST( (HP.INP_YES + HP.INP_NO + HP.UNIDENTIFIED) AS REAL )
        * 100
        , 1
    ) AS 入院率 
FROM
    PREFECTURE AS PF
    INNER JOIN HOSPITALIZATION AS HP
        ON PF.PF_CODE = HP.PF_CODE 
ORDER BY
    入院率 DESC
    , HP.PF_CODE ASC;