Hi, Jeff. Some perf counter values require companion base counter values and must be averaged over two successive readings.
PS C:\> Get-NaPerfCounter processor
BaseCounter : processor_elapsed_time Desc : Percentage of elapsed time that the processor is executing non-idle processes Labels : Name : processor_busy PrivilegeLevel : basic Properties : percent Type : Unit : percent
So to get the processor busy percentage, get the values twice with an interval of a few seconds in between. Then do: