Razar Sharp Company purchased equipment on July 1, 2014, for $70,470. The equipment was expected to have a useful life of three years, or 5,940 operating hours, and a residual value of $2,160. The equipment was used for 1,100 hours during 2014, 2,100 hours in 2015, 1,800 hours in 2016, and 940 hours in 2017. Required: Determine the depreciation expense for the years ended December 31, 2014, 2015, 2016, and 2017 using double-declining method