[quote=Asura]
For the Stormtrooper Corp, yeah. But prior to 0 BBY, the 501st was specifically comprised of Fett Clones only. Meaning that after 19 years, the clone were still in good enough physical shape to serve as Vader's elite death squad.
[/quote]

Where are you getting this from? I admit this isn't my era of preference but as far as I know the clones were a rarity, I know in NuCanon the truth but lets not go there until Episode 7 is out :L