oracle查询每隔5分钟区间内的数据量

SELECT
    COUNT (DISTINCT tmp.PLATE) totalNum,
    tmp.newTime
FROM
    (
        SELECT
            T .LICENSE_PLATE plate,
            TO_CHAR (
                T .create_time,
                'yyyymmddhh24mi'
            ) oldTime,
            -- 原来的时间
            CASE
        WHEN SUBSTR (
            TO_CHAR (T .create_time, 'mi'),
            2,
            1
        ) < 5 THEN
            TO_CHAR (
                T .create_time,
                'yyyymmddhh24'
            ) || SUBSTR (
                TO_CHAR (T .create_time, 'mi'),
                1,
                1
            ) || 0
        ELSE
            TO_CHAR (
                T .create_time,
                'yyyymmddhh24'
            ) || SUBSTR (
                TO_CHAR (T .create_time, 'mi'),
                1,
                1
            ) || 5
        END AS newTime -- 时间段伪列     
        FROM
            B_TRACK T
        WHERE
            T .create_time >= TO_DATE (
                '20180703000000',
                'yyyymmddhh24miss'
            )
        ORDER BY
            T .create_time ASC
    ) tmp
GROUP BY
    tmp.newTime
ORDER BY
    tmp.newTime DESC