Northern Specialties just purchased inventory-management computer software at a cost of $1,369,950. Cost savings from the investment over the next six years will produce the following cash flow stream: $163,340, $223,240, $373,600, $554,250, $684,320, and $631,740. What is the payback period (in years) on this investment? (Round answer to 2 decimal places,e.g. 15.25.)