Thank you for your message.
There is no way to get this information from the FileMaker Server Admin Console (which I am assuming you are wanting to do.)
You'd have to create a "13th" solution that ran a script to open up the other 12 solutions and get the "RecordCount" from each of them and store them in the "13th" solution for viewing.
With that said, this is a good suggestion for future versions of FileMaker Server and specifically the FileMaker Server Admin Console.
Thanks. I just created a temp layout that accessed each table and counted the records. I then added them up manually.