Five deposits of 650 are made into a fund at 3-year intervals with the first deposit at the beginning of the first year. The fund earns interest at an annual effective rate of 3% during the first six years and at an annual effective rate of 6% after that. There is only one additional deposit of 400 at t=24. This time the additional deposit of 600 is NOT made at t=21. Calculate the annual effective yield rate earned over the investment period ending at the end of the twenty-seventh year