[Users] How can I determine "real" CPU consumption

[Leandro Anthonioz]

Hi, I need determine actual CPU consumption of each VPS running in a HN.
If I understood correctly, "Current CPU Utilization" output of vzcpucheck
command display static information about configured minimal guaranteed 
CPU share (cpuunits),  
but not "real" (I mean actual, dynamic) CPU consumption. How can I 
determine actual CPU consumption?
 
Thanks in advance!