A currently owned machine with a market value of $90,000 is expected to have a remaining maximum useful life of 5 years. It is estimated future market values are $60,000, decreasing by $10,000 per year thereafter. The operating cost is expected to be $50,000 the first year, $55,000 the second, and the amount is increasing by $5,000 each year thereafter. At an interest rate of 20% per year, determine the economic service life and the corresponding AW value for this defender