SELECT PREF.PF_CODE AS '都道府県コード', PREF.PF_NAME AS '都道府県名', R_INP.'入院率' FROM PREFECTURE AS PREF
JOIN (
  SELECT PF_CODE, ROUND(CAST(INP_YES AS REAL) / (INP_YES + INP_NO + UNIDENTIFIED) * 100, 1) AS '入院率' FROM HOSPITALIZATION
  ) AS R_INP
  ON PREF.PF_CODE = R_INP.PF_CODE
;