Introducing a new product requires an immediate investment in plant facilities of $180 000 with a disposal value of $45 000 after seven years. The facilities will require additional capital outlays of $50 000 each after three and five years. Net returns on the investment are estimated to be $75 000 per year for each of the first four years and $50 000 per year for the remaining three years. Determine the rate of return on investment (correct to the nearest 10th of a percent)