SELECT 
  PT.PF_CODE AS 都道府県コード, 
  P.PF_NAME AS 都道府県名,
  PT.TOTAL_AMT AS 総人口2015年,
  PT2020.TOTAL_AMT AS 総人口2020年,
  ROUND(100.0 * PT2020.TOTAL_AMT / PT.TOTAL_AMT, 0) AS RATE
FROM 
  POPU_TRANSITION AS PT 
JOIN 
  PREFECTURE AS P ON P.PF_CODE = PT.PF_CODE 
JOIN 
  POPU_TRANSITION AS PT2020 ON PT2020.PF_CODE = PT.PF_CODE 
  AND PT2020.SURVEY_YEAR = 2020 
WHERE
  PT.SURVEY_YEAR = 2015 
  AND PT2020.TOTAL_AMT >= PT.TOTAL_AMT
ORDER BY
  RATE DESC, 
  PT.PF_CODE ASC;