select PF_CODE as 都道府県コード,PF_NAME as 都道府県名, ROUND(1.0*INP_YES/(INP_YES+INP_NO+UNIDENTIFIED),1) as 入院率 
  from (select * from HOSPITALIZATION inner join PREFECTURE on HOSPITALIZATION.PF_CODE = PREFECTURE.PF_CODE)
    ORDER BY 入院率 DESC;