select 	a.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(a.INP_YES AS REAL) /
        CAST( (a.INP_YES + a.INP_NO + a.UNIDENTIFIED) AS REAL )
        * 100
        , 1
    ) AS 入院率 
from HOSPITALIZATION as a
left outer join PREFECTURE as b
on a.PF_CODE=b.PF_CODE
order by round(((INP_YES*100) / (INP_YES+INP_NO+UNIDENTIFIED)),1)  desc,a.PF_CODE asc