XYZ company purchased a delivery van on January 1 2000 for $80000. At the time of purchase it was estimated that the van would be used for 8 years with a $20000 for trade-in value. On January 1, 2004. The company decided to revise the useful life of 10 years and revise th. residual value to $15000. Using the straight-line depreciation, determine the book value on January 1, 2004, and the revised depreciation for 2004.