Way of bucketizing entities

I would like to create some sort of system to bucketize/group linux servers in our test network to determine which ones are being used the most based on their performance over a 90 day period
servername, diskusage, mhz, cpu,network.

The buckets I would like to put them in is: high, medium, low. This will help us determine if a machine is not being used fully and maybe needs to be shutdown.

Currently I have the following values that I got from the data I have using excel. I was going to play with some sort of curve bell calculation but way out of my league here

Count 3677
Min 1
Max 100
Mean 3
Standard Deviation 7.93

Thanks
Median 1