Refer to Case 7-1.

A business purchased a machine that had a total cost of $220,000 and a residual value of $20,000. The asset is expected to service the business for a period of 10 years or produce a total of 1,000,000 units. The machine was purchased January 1st of the current year and has been in service one complete year. 

Now assume the business uses the units-of-production method. If the asset produces 250,000 units in year one and 200,000 units in year two, what is book value at the end of year two?