SELECT IM.PORT_CODE AS "港コード",
    PORT.PORT_NAME AS "港名",
    SUM(
        CASE
            WHEN IM.KIND_CODE = 110 THEN IM.AMT
            ELSE 0
        END
    ) AS "入国者数",
    SUM(
        CASE
            WHEN IM.KIND_CODE = 120 THEN IM.AMT
            ELSE 0
        END
    ) AS "出国者数",
    SUM(
        CASE
            WHEN IM.KIND_CODE = 110 THEN IM.AMT
            ELSE 0
        END
    ) - SUM(
        CASE
            WHEN IM.KIND_CODE = 120 THEN IM.AMT
            ELSE 0
        END
    ) AS "差分"
FROM IMMIGRATION AS IM
    INNER JOIN PORT ON IM.PORT_CODE = PORT.PORT_CODE
WHERE IM.GROUP_CODE = 120
GROUP BY IM.PORT_CODE
HAVING SUM(
        CASE
            WHEN IM.KIND_CODE = 110 THEN IM.AMT
            ELSE 0
        END
    ) > SUM(
        CASE
            WHEN IM.KIND_CODE = 120 THEN IM.AMT
            ELSE 0
        END
    )
ORDER BY "差分" DESC,
    "港コード" DESC