Same set, different string aging

[maturanesa]

I have the same set since sep 2010 (fender nickels), and the E and A strings seems to be much more dead (less sustain with a dull tone) than D and G.
Is there any fact with aging and gauge? or aging and register? could be the brand or that particular set?
Or maybe i just play more the E and A than the D and G

[tylerwylie]

Fender strings are known to not last long at all... but usually my thinner strings die first....

[steamthief]

I've found Fender strings to last longer than most I've tried. I'd guess it's playing the E and A more often. Nine months is a pretty good life for rounds.