Add a driver for "Growth in reduction in operating costs"; this growth is a one time shift, for example, if we thought operating costs would decrease by $1 each year and the user enters 0.5 for this driver, the decrease would be $1.5 each and every year. Initially there is no change in savings but I want you to do a part d} where you evaluate the NPV and lFtFt of the cash flows with a 3.5 % growth starting in year 2