select a.PF_CODE as '都道府県コード',
a.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(b.INP_YES AS REAL) /
        CAST( (b.INP_YES + b.INP_NO + b.UNIDENTIFIED) AS REAL )
        * 100
        , 1
    ) AS 入院率
from HOSPITALIZATION as b
inner join PREFECTURE as a
on b.PF_CODE = a.PF_CODE
order by 入院率 desc, '都道府県コード';