9. The Dallas Company purchased a delivery van in 1999. At the time of purchase, the vans service life was estimated to be ~ years with a salvage value of S500. The company has been using the straight-line method of depreciation. During 2002. the company determined that because of extensive use, the vans ser\'ice life would be only 5 years with no salvage value. Also, the company has decided to change the depreciation method used from straight-line to the sum-of-the-years -digits method. How would these changes be treated?