An analyst is evaluating her bond portfolio. One of her zero coupon bonds will mature in 15 years and the spot rate is 4%. The analyst expects that there would be two equally possible scenarios one year from today. In the first scenario the spot rate would be 2% and in the second scenario the spot rate would be 5%. Please help her to estimate the expected one year return (in percentage terms) of the bond. Note that all bonds are semi-annual.