So when one CPU core is fully loaded, it reads 100%, two cores read 200% etc. I noticed high-end rigs today have 24 CPU cores, in which case when one core is loaded, it would read 4,166666666666667% for one fully loaded core by default. 100% style reading looks much nicer and easier to tell how loaded CPU really is with various workloads.

Those 4% in this instance could be hiding the fact that some program is just stuck spinning in a loop.