radar, inc. purchased a van on january 1, 2016 for $830,000. Estimated life of the van was five years, and its estimated residual value was $104,000. Radar uses the straight-line method of depreciation. At the beginning of 2018, the corporation revised the total estimated life of the easset from five to six years. The estimated residual value remained the same as estimated earlier. Calculate the depreciation expense for 2018