select 
PP.PF_CODE as 都道府県コード
,PF.PF_NAME as 都道府県名
-- 2015年のTOTAL_AMT → 総人口2015年
-- 2020年のTOTAL_AMT → 総人口2020年
-- 人口増加率を%で表示(小数点以下は四捨五入) → 人口増加率
,sum(case when PP.SURVEY_YEAR = 2015 then TOTAL_AMT else 0 end)  as 総人口2015年
,sum(case when PP.SURVEY_YEAR = 2020 then TOTAL_AMT else 0 end)  as 総人口2020年
,round (
  cast(sum(case when PP.SURVEY_YEAR = 2015 then TOTAL_AMT else 0 end) as real )/
  cast(sum(case when PP.SURVEY_YEAR = 2020 then TOTAL_AMT else 0 end) as real )
  * 100
  ,0
) as 人口増加率
from
 POPU_TRANSITION as PP
 inner join PREFECTURE as PF
 on PP.PF_CODE = PF.PF_CODE
 group by PP.PF_CODE,PF.PF_NAME
 having sum(case when PP.SURVEY_YEAR = 2015 then TOTAL_AMT else 0 end) < 
        sum(case when PP.SURVEY_YEAR = 2020 then TOTAL_AMT else 0 end) 
 order by 人口増加率 desc, PP.PF_CODE