On January 1, 2002, ABC Company purchased equipment for $100,000. The equipment was assigned an estimated life of 10 years and a salvage value of $10,000. On January 1, 2005, ABC Company decided the life of the equipment should be revised from 10 to 15 years with a salvage value of $4,000 at the end of the 15 years. Calculate the book value of the equipment at December 31, 2009 assuming ABC Company uses the straight line depreciation method. Do not use decimals in your answer.