A machine purchased 9 years ago for $45,000 is expected to have the salvage values and operating costs as shown below. It can be disposed of now at a market value of $8,000. A replacement machine will cost $125,000 and will have a $10,000 salvage value after its 10-year life. Its annual operating cost is expected to be $31,000. At an interest rate of 15% per year, determine how many more years, if any, the company should retain the existing machine