With the approval of the President, the Secretary of the Treasury may increase by regulation the interest rate or investment yield on an offering of bonds issued under this chapter that are described in sections 405(b) and 409(a) of the Internal Revenue Code of 1954 (, 409(a)), as in effect before the enactment of the Tax Reform Act of 1984. The increased yield shall be for interest accrual periods specified in the regulations so that the interest rate or investment yield on the bonds for those periods is consistent with the interest rate or investment yield on a new offering of those bonds.26 U.S.C. 405(b)