kern.cp_time question

[walt]

$ sysctl kern.cp_time
kern.cp_time: 2488290009 0 0 0 1715301177 0 8513897 0 1597781206 5

The numbers above (I think) are counters, related in some way
to the categories of 'user', 'nice', 'sys', 'intr', and 'idle'.

Could someone explain to me what 'things' are actually being
counted -- and maybe where in the kernel code the counters are
actually defined and used?

I've been reading thru the code for 'top' 'sysctl' 'libkinfo'
'systat' and I'm getting a bit lost in the details.

Thanks!