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