Should a wheel be centered to the frame when seated properly in the dropouts?



This is the rear wheel on my caad9. I've not touched the wheel since I bought the bike new but noted this is a bit off center(2mm). The wheel spins true but looks to need some tweaking to the dish. Should I adjust the wheel a few centimeters over to center it on the frame? Hadn't noticed this before but I'm working to install a rear fender and this is not going so well with this being off center.

Appreciate any input.

somegeek