Assume that the pure expectations theory of the term structure is correct. the interest rate today on a 9-year security is 6.30 percent, and the interest rate today on a 15-year security is 7.80 percent. Finally, the interest rate on a 3-year security to be bought at year 9 and held over years 10, 11, and 12 is 6.80 percent. Determine the average annual return that investors today must expect that they will receive from investing in a 3 year security in 12 years. That is buying the security at year 13 and holding it over years 13,14 and 15.