I guess it now been 1 year for me, they all still work well. But I have not inspected them lately. Watt meter and air draw is what i look at. Have you check your Watts draw?
I think the wear going to be different in each pump and even each mod... Weather you used the thicker matrial or thiner4,5,6, how you trimed it, the size of the volute, number of layers...
FWIW Im glad they lasted a year. Best $4.00 Ive ever spent in this hobby