The cost of equipment purchased by Charleston, Inc., on June 1, 2014, is $136,170. It is estimated that the machine will have a $7,650 salvage value at the end of its service life. Its service life is estimated at 7 years, its total working hours are estimated at 64,260, and its total production is estimated at 803,250 units. During 2014, the machine was operated 9,180 hours and produced 84,150 units. During 2015, the machine was operated 8,415 hours and produced 73,440 units. Compute depreciation expense on the machine for the year ending December 31, 2014, and the year ending December 31, 2015, using the following methods. (Round answers to 0 decimal places, e.g. 45,892.) Straight-line Units-of-output Working hours Sum-of-the-years'-digits Double-declining-balance (twice the straight-line rate)