Excessive brake pad wear 2017 A4?
 

Just came home from the dealership after am early 20k mile service to find front brake pads down to 4 mm, back pads at 8. I am the original owner of the car which has only 16,600 miles on it. Does this seem excessive? I see pads typically last from 30k to 65k and, while I am a stop and go/city driver (Sacramento), none of my other cars have ever had this issue.

Thoughts greatly appreciated!