An item of equipment acquired on January 1, at a cost of $100,000, has an estimated use of 50,000 hours. During the first three years, the equipment was used 11,000, 8,000, and 7,000 hours, respectively. The equipment has an estimated life of five years and an estimated salvage of $10,000.

Required:

Determine the depreciation for each of the three years, using the straight-line method, the double declining-balance method, the sum-of-the-years'-digits method, and the units-of-production method.