Kprobe scan question

I am new to this, and would like to know what the 0-45 scale in the first graph represents, mainly because all the other scans I looked at do not go all the way up to 45.
Basically, is this a good burn, or is there something very wrong with it? It was burned with 451 at 4x and read with same, using recordnow.

Kprobe tutorial

Interpreting PI/PO

I guess you use Ritek G04 media. My results are even worse. I get an average pi of 49.867 and po of 0.338.

But that is still a good result. The discs play fine on all standalone players I could test.

The quality of Ritek G04 media may vary from batch to batch. But your result is still good.

yes, its ritek 4x -r media.
Thanks, I finally figured out how to understand those results.
I was just wondering because for most scans i saw the first graph is kind of sloped, or goes up and down, and mine is pretty much straight. But I suppose that just means errors are pretty much at same level throughout the disk in my case.