with tmp1 as(
select 
    i.port_code 
    ,port_name
    ,sum(case when i.GROUP_CODE="120" and kind_code="110" then AMT else 0 end) as imm
    ,sum(case when i.GROUP_CODE="120" and kind_code="120" then AMT else 0 end) as dep
from IMMIGRATION i
left join GRP g on i.GROUP_CODE=g.GROUP_CODE
left join PORT p on i.PORT_CODE=p.PORT_CODE
group by 1
)
select 
    port_code as "港コード"
    ,port_name as "港名"
    ,imm as "入国者"
    ,dep as "出国者"
    ,imm-dep as "差分"
from tmp1
where dep<imm
order by 5 desc, 1 desc