Identifying Most Costly Queries by CPU

SELECT TOP 5
    [Query] = [Query],
    [CPU]   = SUM([CPU])

FROM (

    SELECT
        [CPU]   = [Total CPU Used],
        [Query] = dbo.fn_GetSQLNormalized([Parent Query])

    FROM
    (
        SELECT TOP 20
            [Average CPU Used]  = total_worker_time / qs.execution_count,
            [Total CPU Used]    = total_worker_time,
            [Execution COUNT]   = qs.execution_count,
            [Individual Query]  = SUBSTRING(
                qt.text,
                qs.statement_start_offset / 2,
                (CASE
                    WHEN qs.statement_end_offset = -1
                    THEN LEN(CONVERT(NVARCHAR(MAX), qt.text)) * 2
                    ELSE qs.statement_end_offset
                END - qs.statement_start_offset) / 2
            ),
            [Parent Query]      = qt.text,
            [DATABASE Name]     = DB_NAME(qt.dbid)

        FROM
            sys.dm_exec_query_stats qs

        CROSS APPLY
            sys.dm_exec_sql_text(qs.sql_handle) AS qt

        ORDER BY
            [Average CPU Used] DESC

    ) AS Queries

) AS NormalizedQueries

GROUP BY [Query]

ORDER BY [CPU] DESC