WITH ImmigrationData AS (
    SELECT
        PORT_CODE,
        SUM(CASE WHEN GROUP_CODE = '120' AND KIND_CODE = '110' THEN AMT ELSE 0 END) AS 'inbound',
        SUM(CASE WHEN GROUP_CODE = '120' AND KIND_CODE = '120' THEN AMT ELSE 0 END) AS 'outbound'
    FROM IMMIGRATION
    GROUP BY PORT_CODE
)
SELECT
    ID.PORT_CODE AS '港コード',
    PORT.PORT_NAME AS '港名',
    ID.inbound AS '入国者',
    ID.outbound AS '出国者',
    ID.inbound - ID.outbound AS '差分'
FROM ImmigrationData AS ID INNER JOIN PORT ON ID.PORT_CODE = PORT.PORT_CODE
WHERE ID.inbound - ID.outbound > 0
ORDER BY 差分 DESC, ID.PORT_CODE DESC;