SELECT 
    I1.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 
    IMMIGRATION  I1 JOIN IMMIGRATION I2 ON I1.PORT_CODE = I2.PORT_CODE 
    AND I1.GROUP_CODE = I2.GROUP_CODE 
    AND I2.KIND_CODE = 120 
    JOIN PORT P ON I1.PORT_CODE = P.PORT_CODE 
WHERE 
    I1.GROUP_CODE = 120
    AND I1.KIND_CODE = 110
    AND (I1.AMT - I2.AMT) > 0
ORDER BY (I1.AMT - I2.AMT) DESC,I1.PORT_CODE DESC
;