On 2009 January 2, a company purchased and placed in operation a new machine at a total cost of USD 60,000. Depreciation was recorded on the machine for 2009 and 2010 under the straight-line method using an estimated useful life of five years and no expected salvage value. Early in 2011, the machine was overhauled at a cost of USD 20,000. The estimated useful life of the machine was revised upward to a total of seven years. Compute the depreciation expense on the machine for 2011.