If you are running on a factory (on the MOBO and some of the aftermarket cards as well ie: Sound Blaster & gaming cards) soundcard, the numbers for the CPU will be much much higher than if you are using a dedicated external interface.
The internal interface is a bottle neck and it doesn't handle the data MC wants to push through it. For that reason, it will overtax that CPU. The USB based externals running ASIO drivers are like huge pipes that allow all the data through in a timely and efficient manner and as a result the CPU numbers are very low.
The computer itself also plays a part. My lappy would run a project with my Saffire interface and be around 30% fully loaded..... that same project in my custom desktop tower DAW runs at 15% CPU.
Proper soundcard will get that number way down.
On my old lappy, if I loaded a huge project with Ozone and Melodyne, and left them in the mix, it was possible to get up above 65% and somewhere around 80% I would start getting the glitches in sound. Often, that was intentional just to see...... I used bounce to track and other work arounds to get the numbers back below 50% when I saw that happening.
As a side note..... you should shut off and close all other programs while working in MC. All the computer's available resources should be open to MC alone. No word processors, no games, no internet browser.
A proper sound card will make a huge difference in the CPU numbers as well as the over all performance of MC or any other DAW.