A 4% annual coupon bond with a 10-year maturity is priced (in the market) to have a yield to maturity of y=3.5%. An investor with a ten-year horizon is planning to buy the bond, and hold it for ten years, reinvesting the coupons received over that period. She computes her realized compound yield as RCY=4.1%. Then she must be assuming a coupon reinvestment rate of