Dave, I entered and ran the SQL expression you sent. It returned a total of 24132. The total shown in the awards section of LOTW is 24090.
Some how, I have QSOs with a Y that shouldn't have been there. I suspect that it was due to operator error going back to around 2007 - 2008 when I first started using DXLab.
I think the only way to find these errors is a line by line comparison between my LOTW file and my DXKeeper log.