You have been asked to calculate the payback period of the following project. The project has a cost of $225,000. The project has an expected cash flow of $80,000 in year 1, an expected cash flow of $90,000 in year 2, an expected cash flow of $100,000 in year 3 and an expected cash flow of $110,000 in year 4. The required rate of return is 8% compounded annually. How many years does it take for the project to recover its cost? (What is the payback period in years?)