select
	 i.PORT_CODE as 港コード
	,p.PORT_NAME as 港名
	,i.AMT as 入国者数
	,o.AMT as 出国者数
	,i.AMT - o.AMT as 差分
from
	(
		select
			PORT_CODE
			,AMT
		from
			IMMIGRATION as i
			inner join GRP as g
				on i.GROUP_CODE = g.GROUP_CODE
		where
			KIND_CODE = '110'
		and g.GROUP_NAME = '外国人'
	) as i
	inner join (
		select
			PORT_CODE
			,AMT
		from
			IMMIGRATION as i
			inner join GRP as g
				on i.GROUP_CODE = g.GROUP_CODE
		where
			KIND_CODE = '120'
		and g.GROUP_NAME = '外国人'
	) as o
		on i.PORT_CODE = o.PORT_CODE
	inner join PORT as p
		on i.PORT_CODE = p.PORT_CODE
where
	i.AMT > o.AMT
order by
	5 desc, 1 desc