Does anyone have a benchmark on case deflection due to your Knowledge Management or self-service capabilities?

Hi everyone, Isaiah here and I am new to ServiceNow and this community. I am after some KPIs and benchmarks.

In particular:

1) How are you measuring case deflection i.e. your employees don't need to raise a case thanks to your knowledge articles?

2) What kind of % deflection are you seeing or any industry benchmark you might have?

Thanks in advance!