I'm sorry this my be a silly question but how can I tell when something is due to fall off?  So if you have the followin lates Jan 2004 - Mar 2004 (30, 60,90) Do all lates fall off in Jan 2011 or just the one of the lates?

 

I have a number of older lates (varying by company from 2001 - 2004) and would like to send out some GW letters but don't know if its worth it for the really old ones.

 

Thanks