with a as(
select 
POP.PF_CODE,
POP.TOTAL_AMT
from
POPU_TRANSITION as POP
where
SURVEY_YEAR=2015)

,b as(
select 
POP.PF_CODE,
POP.TOTAL_AMT
from
POPU_TRANSITION as POP
where
SURVEY_YEAR=2020)

select
distinct POP.PF_CODE as 都道府県コード,
PREFECTURE.PF_NAME as 都道府県名,
a.TOTAL_AMT as 総人口2015年,
b.TOTAL_AMT as 総人口2020年,
round(cast(b.TOTAL_AMT*100 as real)/cast(a.TOTAL_AMT as real),0) as 人口増加率
from POPU_TRANSITION as POP
inner join a on POP.PF_CODE=a.PF_CODE
inner join b on POP.PF_CODE=b.PF_CODE
inner join PREFECTURE on PREFECTURE.PF_CODE = POP.PF_CODE
order by 人口増加率 desc,都道府県コード asc