Assume McGregor Consultants purchased a building for $445,000 and depreciated it on a straight-line basis over 40 years. The estimated residual value was $90,000. After using the building for 20 years, McGregor realized that the building will remain useful only 14 more years. Starting with the 21st year, McGregor began depreciating the building over a revised total life of 34 years and decreased the residual value to $15, 500. Record depreciation expense on the building for years 20 and 21