SELECT
	p.PORT_CODE as 港コード,
	p.PORT_NAME as 港名,
	i1.AMT as 入国者数,
	i2.AMT as 出国者数,
	(i1.AMT - i2.AMT) as 差分
FROM
	(SELECT
		PORT_CODE,
		AMT
	FROM
		IMMIGRATION
	WHERE
		GROUP_CODE = 120 AND
		KIND_CODE = 110
	) i1,
	(SELECT
		PORT_CODE,
		AMT
	FROM
		IMMIGRATION
	WHERE
		GROUP_CODE = 120 AND
		KIND_CODE = 120
	) i2,
	PORT p
WHERE
	i1.PORT_CODE = i2.PORT_CODE AND
	i2.PORT_CODE = p.PORT_CODE AND
	i1.AMT >= i2.AMT
ORDER BY
	差分 DESC,
	港コード DESC