select 
 H.PF_CODE as '都道府県コード',
 P.PF_NAME as '都道府県名',
 ROUND(H.INP_YES*100/(H.INP_YES+H.INP_NO+H.UNIDENTIFIED),2) as '入院率'
from
 HOSPITALIZATION as H
inner join
 PREFECTURE as P
ON
 H.PF_CODE= P.PF_CODE
group by H.PF_CODE;