A company aquired equipment for 20,000. The company uses straight-line depreciation and estimates a residual value of 2,000 and a four-year service life. At the end of the second year the compnay estimates that the equipment will be useful for four additional years, for a total service life of six years rather than the original four. At the same time, the company also changed the estimated residual value to 1,000 from the original estimate of 2,000. Calculate how much the company should record each year for depreciation in years 3 to 6