Abnormally high CPU usage

According to top/htop /usr/lib64/xfce4/panel/plugins/libcpufreq.so is the worst offender in terms of CPU usage.

My CPU is running at 600Mhz, and this plugin shows around 17% CPU usage which is simply too much.

This plugin CPU usage rivals X.org's server entire CPU usage which should never happen - see the attached screenshots.

CPU time:

This plugin: 140 hours
X.org server: 250 hours.

I have a dual core Core i5 6200U CPU.