From my experience with my own vehicles the rear brakes do wear out faster than the front brakes.
I always check all my brake pads and brake shoes and when I need to replace the brake shoes on the rear of the truck the front brake pads are still pretty thick and have more miles on them.
Someone told me it's because of the weight of the vehicle and that the back brakes do most of the stopping while the front brakes are just there to help stop the weight of the vehicle.
So your rear brakes should normally wear out much faster than the front brakes.
Always do check your brake pads and brake shoes if you have them on both the front and rear of the vehicle after at least 5 years of driving.
Some brake shops will do a free brake inspection and let you know if the brake pads or brake shoes are okay or need replacing.