MS SQL Server Query - CPU waits

Select signal_wait_time_ms=sum(signal_wait_time_ms)
,'%signal waits' = cast(100.0 * sum(signal_wait_time_ms) / sum (wait_time_ms) as numeric(20,2))
,resource_wait_time_ms=sum(wait_time_ms - signal_wait_time_ms)
,'%resource waits'= cast(100.0 * sum(wait_time_ms - signal_wait_time_ms) / sum (wait_time_ms) as numeric(20,2))
From sys.dm_os_wait_stats