Step 1. Create a new folder. Give it a name that indicates it only contains race cards run at TAM during calendar year 2012.
Note: TAM2012 works for this purpose.
Step 2. Use Windows Explorer to copy data and results files for all TAM 2012 race cards onto your new folder.
Step 3. Run a Build Database routine in Mode 1 on your new folder.
At this point you have a database that (only) contains races run at TAM during calendar year 2012. (Any and all R&D you do using this database is therefore based on TAM 2012 races.)