Averages can be misleading, you could have a server idling for 16 hours, and breaking for 8.

A better technique is to have buckets with how long the server is in that state.

A histogram for a day showing CPU at 0-20, 21 to 40, 40 to 60, 60 - 80, 80 to 100 with how long it spent there is one way of doing it