Some more questionable figures:
First off, it should be 1914 B18 Blankets, and not B14 Blankets. And then, the Excel Pop Schedule shows only 2 ungraded Jacksons out there, that is it. PSA doesn't grade the B18 Blankets apparently, so showing 0 graded by them is correct. But for SGC, well here's their Pop Report for B18 Blankets, and looks like 46 graded, not the 0 shown on the Excel Pop Schedule.
https://www.gosgc.com/pop-report/res...nkets/Baseball
And as for Ryan's question on the T210 Jacksom Old Mill cards, I'm guessing there may be a mix-up and incorrect inclusion of different players also named Jackson, that appear in other Series of the T210 cards. IIRC, Joe Jackson appears in Series 8 only. Per PSA, they show a total of 9 graded T210 Joe Jackson cards, which agrees with the Excel Pop Schedule, while SGC appears to show a total of only 8 graded Joe Jackson cards, which definitely does not agree with the 67 shown per the Excel Pop Schedule.
https://www.psacard.com/pop/minor-le...series-8/81318
https://www.gosgc.com/pop-report/res...10%29/Baseball
These two examples, plus the earlier T200 cards, are the only three Joe Jackson cards I checked the graded numbers on between the actual PSA and SGC Pop Reports and the Excel Pop Schedule, and all three show major discrepancies. So, I'm not sure how accurate the rest of that Excel Pop Schedule actually is.