A software company that installs systems for inventory control using RFID technology spent $$640,000$ per year for the past $3$ years in developing their latest product. The company optimistically hopes to recover its investment in $5$ years on a single contract beginning immediately $($year $0).$ The company is negotiating a contiact that will pay $$275,000$ now and a to$-$beagreed$-$upon annual increase of a constant amount each year through year $5.$ How much must the income increase $($an arithmetic gradient$)$ each year if the company wants to realize a return of $10\mathrm{.}00\%$ per year? $($Round the final answer to three decimal places.$)$