SELECT
    im.port_code AS 港コード
    , port_name AS 港名
    , MAX(CASE WHEN im.kind_code = 110 THEN amt ELSE NULL END) AS 入国者数
    , MAX(CASE WHEN im.kind_code = 120 THEN amt ELSE NULL END) AS 出国者数
    , MAX(CASE WHEN im.kind_code = 110 THEN amt ELSE NULL END) - MAX(CASE WHEN im.kind_code = 120 THEN amt ELSE NULL END) AS 差分
FROM
    immigration im
    INNER JOIN
        port
        ON im.port_code = port.port_code
WHERE
    im.group_code = '120'
    AND im.kind_code IN ('110', '120')
GROUP BY
    1, 2
HAVING
    MAX(CASE WHEN im.kind_code = 110 THEN amt ELSE NULL END) > MAX(CASE WHEN im.kind_code = 120 THEN amt ELSE NULL END)
ORDER BY
    5 DESC, 1 DESC