date Posted: Apr 25, 2007 1:41 AM
There is a comment made in Republic Commando: Hard Contact regarding the age of the clones and the ways that more are being produced. Can't remember the exact comment though.
Also, during the Clone Wars, Clones were being produced/created on many planets, and at accelerated speeds, which lead to some problems, mainly mental (Spaarti cylinders get a mention in one of the online / insider stories (Hero of Cartao I think)).