select 
po.PF_CODE as 都道府県コード,
pf.PF_NAME as 都道府県名,	
po.TOTAL_AMT as 総人口2015年,
po2020.TOTAL_AMT as 総人口2020年,
round(cast(po2020.TOTAL_AMT as real)/cast(po.TOTAL_AMT as real)*100) as 人口増加率

from
POPU_TRANSITION as po
inner join PREFECTURE as pf
on po.PF_CODE = pf.PF_CODE
inner join
POPU_TRANSITION as po2020
on po2020.SURVEY_YEAR = 2020
and po.PF_CODE = po2020.PF_CODE

where
po.SURVEY_YEAR = 2015
and po.TOTAL_AMT < po2020.TOTAL_AMT

order by 
人口増加率 desc,都道府県コード;