A new asset is available for $220,000. O&M costs are $22,000 each year for the first five years. $24,000 in year 6, $28,000 in year 7, and $30,000 in year 8. Salvage values are estimated to be $150,000 after one year and will decrease at the rate of 20% per year thereafter. At a MARR of 10%, determine the economic service life of the asset.