nvidia-smi how to get valid values.

Quick question about nvidia-smi. How to get valid values for GPUGraphicsClockOffset option?
I know, i can use something like:

nvidia-settings -a [gpu:0]/GPUGraphicsClockOffset[3]=-1000
The valid values for ‘GPUGraphicsClockOffset’ are in the range -200 - 1200 (inclusive).

…and then parce the output, but if there a better way to do it?