Novell Electronics recently bought a patent that will allow it to bring a new product to market in 2 1/2 years. Sales forecasts indicate that the product will increase the quarterly profits by $18,000. If the patent cost $150,000, how long after the date of the patent purchase will it take for the additional profits to repay the original investment along with a return on investment of 4.5% compounded quarterly? Assume that the additional profits are received at the end of each quarter.