Not exactly the same as a pop report for PSA, but I often use the PSA set registry to figure out pops, especially because I don't have a PSA membership right now. For N300 Mayo, you can go to:
http://www.psacard.com/SetRegistry/a...t.aspx?s=10546
From this registry, it looks like there are 3 cards at PSA2 and 3 cards that are graded higher.