Glow Co. purchased machinery on January 2, 2009, for $660,000. The straight-line method is used and useful life is estimated to be 10 years, with a $60,000 salvage value. At the beginning of 2015 Glow spent $144,000 to overhaul the machinery. After the overhaul, Glow estimated that the useful life would be extended 4 years (14 years total), and the salvage value would be $30,000. The depreciation expense for 2015 should be