Depreciation = (Cost - Residual value) / Useful life

On April 1, 2006, Company A purchased an equipment at the cost of $140,000. This equipment is estimated to have 5 year useful life. At the end of the 5th year, the salvage value (residual value) will be 20,000. Company A recognizes depreciation to the nearest whole month. Calculate the depreciation expenses for 2006, 2007 and 2008 using straight line depreciation method.