For Nero CD Speed Disc Quality Scan how many PI/PIF errors are too many?

With specific reference to Nero CD Speed Disc Quality Scan,

How much PI/PIF errors is considered to make up a bad disc?
And what is the typical value for PI/PIF errors for good discs like Taiyo-Yuden.

Where can I find sample screenshots of scans of TY, Ricoh and Mitsubishi discs?

Btw I’m using a BenQ 1620Pro with the T-Version firmware.

Many tks!

Look at the Benq and media forums, there are lots of scans.