Accufab regulator pressure setting stability

[joed]

I just checked my FP for the first time in years. AFR was going high. At least 5-6 years maybe more. Anyway I found it at 37 psi down from 43-44. Anyone else see this "drift"? I know it's got a spring in it so it may change over time...? A sign of something?
Car running better now I'm going to check once a year now tho. Thanks.