If the rate of participation in the annuity contract and custodial account is less than 2 percent of active members in the Defined Benefit Program upon the completion of the initial five years of administration, the board may elect to terminate the offering of the annuity contract and custodial account as described in Section 403(b) of the Internal Revenue Code of 1986. The board shall provide two years’ notice to the annuity contract and custodial account participants of its intention to terminate.