SELECT
    P.PORT_CODE AS "港コード",
    P.PORT_NAME AS "港名",
    IIN.AMT AS "入国者数",
    IOUT.AMT AS "出国者数",
    IIN.AMT - IOUT.AMT AS "差分"
FROM
    GRP AS G
INNER JOIN
    IMMIGRATION AS IIN ON IIN.GROUP_CODE = G.GROUP_CODE AND IIN.KIND_CODE = "110"
INNER JOIN
    IMMIGRATION AS IOUT ON IOUT.GROUP_CODE = G.GROUP_CODE AND IOUT.KIND_CODE = "120"
INNER JOIN
    PORT AS P ON IIN.PORT_CODE = P.PORT_CODE AND IOUT.PORT_CODE = P.PORT_CODE
WHERE
    GROUP_NAME = "外国人" AND IIN.AMT > IOUT.AMT
ORDER BY
    "差分" DESC,
    "港コード" DESC