The repayment plan for a loan with an interest rate of 5.0% totaling 20,500 now is to fully pay off the loan in 11 years using end of year payments beginning at 1300 and increasing by the same amount beginning in the second so that the loan is completely paid off at the time of the last payment. What is the amount of the increase/decrease needed each year, the linear gradient, that results in the loan payoff as planned?