Equipment was acquired on January 1, 2013, at a cost of $75,000. The equipment was originally estimated to have a salvage value of $5,000 and an estimated life of 10 years. Depreciation has been recorded through December 31, 2016, using the straight-line method. On January 1, 2017, the estimated salvage value was revised to $7,000 and the useful life was revised to a total of 8 years. Determine the depreciation expense for 2017.