Special equipment can be designed and built for $80,000. This equipment will have a salvage value of $70,000 in year 1, which will decrease b y $10,000 through year 8. Operation and maintenance costs will start at $18,000 in year 1, and increase by 5% per year through year 8. The organization proposing this design can borrow money with 9% annual interest rate. Using tabular approach, find the economic life of this equipment.