Wrong CPU average usage calculation?

[JsBergbau]

I have 12 cores, one core is completly utilized. Using math this should lead to 1/12=8,33 % CPU usage.
However htop shows mainly something between 3 % and 5 % cpu usage. Am I thinking here something wrong or does htop calculate the average CPU usage wrong?

[BenBE]

Which OS/distro? What version of htop are you using?

[JsBergbau]

Thank you very much for your fast reply.

I'm using:
Linux debian 5.10.0-15-amd64 #1 SMP Debian 5.10.120-1 (2022-06-09) x86_64 GNU/Linux
htop 3.0.5

[JsBergbau]

I've also compiled latest release 3.2.1. It shows the same average CPU usage as 3.0.5. However it shows only 115 MB of memory used, whereas 3.0.5 shows 516 MB used. But thats for a different issue #1051
3.2.1

3.0.5