The redemption value of a bond on a given interest accrual date during an extended maturity period or periods will be the higher of the values produced using either the applicable guaranteed minimum investment yield or the appropriate market-based variable investment yield. The calculation of these yields and the resulting redemption values are described below:

(a) Guaranteed minimum investment yield and resulting values during an extended maturity period. A bond may be subject to one guaranteed minimum investment yield during its original maturity period and to another such yield during each of its extended maturity periods.

(1) Bonds entering an extended maturity period from May 1, 1989, through February 1, 1993. Bonds that entered an extended maturity period from May 1, 1989, through February 1, 1993, had a guaranteed minimum investment yield of 6 percent per annum, compounded semiannually, during that extended maturity period.

(2) Bonds entering an extended maturity period on or after March 1, 1993. Bonds that entered or enter an extended maturity period on or after March 1, 1993, have a guaranteed minimum investment yield of 4 percent per annum, compounded semiannually, during that extended maturity period, or the guaranteed minimum investment yield in effect at the beginning of that period.

(3) Determination of values for a bond during extended maturity periods. In order to determine values for a bond during its first extended maturity period, we determine the value of the bond at the end of its original maturity period using the guaranteed minimum investment yield applicable to that period. This value is then used as the base upon which interest accrues during the first extended maturity period at the applicable guaranteed minimum investment yield for that period. We use the value thus attained at first extended maturity as the base upon which interest accrues during the second extended maturity period at the applicable guaranteed minimum investment yield for that period. We then compare the resulting semiannual values with the corresponding values determined using only the applicable market-based variable investment yields.

(b) Market-based variable investment yield and resulting values during an extended maturity period. For a bond beginning an extended maturity period, the market-based variable investment yield from its first semiannual interest accrual date occurring on or after November 1, 1982, or its issue date, whichever is later, to each semiannual interest accrual date occurring on or after November 1, 1989, will be 85 percent, rounded to the nearest one-hundredth of one percent, of the arithmetic average of the market yield averages for the appropriate number of 6-month periods involved, beginning with the period from May 1, 1982, or the 6-month period that most recently ended before the issue date, whichever period occurs later. We use the value of a bond on its first semiannual interest accrual date occurring on or after November 1, 1982, or its issue date, whichever is later, as the base upon which interest accrues during the extended maturity period at the applicable market-based variable investment yield. As described above, the bond will receive the higher of the two values: One value produced using the applicable market-based variable investment yield; and, the other value produced using the guaranteed minimum investment yield.