SELECT
    HOSPITALIZATION.PF_CODE AS "都道府県コード",
    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(INP_YES AS REAL) /
        CAST( (INP_YES + INP_NO + UNIDENTIFIED) AS REAL )
        * 100
        , 1) AS "入院率" 
FROM 
    HOSPITALIZATION INNER JOIN PREFECTURE ON HOSPITALIZATION.PF_CODE = PREFECTURE.PF_CODE
ORDER BY 
    "入院率" DESC,
    HOSPITALIZATION.PF_CODE ASC;