WITH IN_IMG AS (
  SELECT PORT_CODE
    , AMT
  FROM IMMIGRATION
  WHERE GROUP_CODE = '120' AND KIND_CODE = '110'
), OUT_IMG AS (
  SELECT PORT_CODE
    , AMT
  FROM IMMIGRATION
  WHERE GROUP_CODE = '120' AND KIND_CODE = '120'
)
SELECT PORT_CODE AS '港コード'
  , PORT_NAME AS '港名'
  , IN_IMG.AMT AS '入国者数'
  , OUT_IMG.AMT AS '出国者数'
  , IN_IMG.AMT - OUT_IMG.AMT AS '差分'
FROM PORT
JOIN IN_IMG USING(PORT_CODE)
JOIN OUT_IMG USING(PORT_CODE)
WHERE IN_IMG.AMT > OUT_IMG.AMT
ORDER BY 5 DESC, 1 DESC;