Rear Brake change interval..98 Camry 4 cyl.

I know the shoes wear according to how the car is driven, but in normal service, roughly how often do the rear shoes need changing?

My wife's 98 XLE 4 cylinder has rear drums and currently has 83,000 miles on it and still has the original shoes and they look to be in pretty good shape. I had the drums off about a thousand miles ago to check on them. They still had plenty of meat left on thme. I just cleaned the brake dust out of the drums, relubed the 6 points on each backing plate that the shoes contact with high temperature brake grease and adjusted them manually. I am amazed by how long they are lasting.

Mike