Erratic Ltd. owns an asset with an original cost of $300,000. On acquisition, management determined that the useful life was 15 years and the residual value would be $30,000. The asset is now 8 years old, and during this time there have been no revisions to the assessed residual value. At the end of year 8, management reviewed the useful life and residual value and has determined that the useful life can be extended to 20 years in view of the maintenance program adopted by the company. As a result, the residual value will reduce to $15,000. How would the changes in estimates be effected?