Peter, the factory call it wear and tear, irrespective of age or mileage and ignoring the fact there was a faulty batch of cables. I was told that one snapped when the car was 3 months old and the factory refused to replace it under the warranty. With modern cables, stainless and running in Teflon and not requiring lubrication, there is no reason the cable should not last for many years.
My inner cable had not corroded through and I think was stainless. The wire spiral reinforcing of the outer sheath had corroded and snapped and the sharp edges worn through the cable.
