SELECT 
  p.PF_CODE as "都道府県コード", 
  p.PF_NAME as "都道府県名", 
  ROUND(h.INP_YES/sum(h.INP_YES + h.INP_NO + h.UNIDENTIFIED), 2) as "入院率" 
FROM HOSPITALIZATION as h
JOIN PREFECTURE as p
    ON h.PF_CODE = p.PF_CODE;