This object provides how many percentage of total CPU
resource is used.
Usually GHz is used for measuring CPU power. Since GHz
is too large for measuring some CPU usage categories,
KHz is used as the measuring unit. The system speed
(in KHz) multiply by the fraction of each CPU sections
(e.g. idle, nice, user, etc.) to get the CPU KHz of
each category; Khz is used as the unit for all the CPU
categories below.