Total User Time is the average percentage of non-idle time all processors spend in user mode. It is the sum of Processor: ...

% Total User Time is the average percentage of non-idle time all processors spend in user mode.  It is the sum of Processor: % User Time for all processors on the computer, divided by the number of processors.  System: % Total User Time and System: % Total Privileged Time sum to % Total Processor Time, but not always to 100%.  (User mode is a restricted processing mode designed for applications, environment subsystems, and integral subsystems.  The alternative, privileged mode, is designed for operating system components and allows direct access to hardware and all memory.  The operating system switches application threads to privileged mode to access operating system services). This counter displays the average busy time as a percentage of the sample time.