A fulfillment center has been packaging boxes by hand since the company was first founded. After some advancements in technology, the fulfillment center is considering purchasing a robot to package some of the products sold. Packaging boxes by hand costs the company $$500/$yr in personal$-$protective$-$equipment for the person packaging the items plus a cost of $$0\mathrm{.}25$ per packaged unit. The robot alternative would cost $$40,000$ to purchase plus $$0\mathrm{.}09$ per packaged unit. If the fulfillment center anticipates to send out $8,000$ packages per year, the payback period after implementing the robot to package boxes as opposed to continue packaging by hand is most nearly: