(a) Any police officer who has at least 10 years of creditable service in the Fund may transfer to this Fund credits and creditable service accumulated under any other pension fund or retirement system established under Article 8 or 12 of this Code, by making application and paying to the Fund before January 1, 1990 the amount by which the employee contributions that would have been required if he had participated in this Fund during the period for which credit is being transferred, plus interest, exceeds the amount actually transferred from such other fund or system to this Fund under item (1) of Section 8-226.5 or item (1) of Section 12-127.5.
     (b) Any police officer who has at least 10 years of creditable service in the Fund may transfer to this Fund up to 48 months of creditable service accumulated under Article 9 of this Code as a correctional officer with the county department of corrections prior to January 1, 1994, by making application to the Fund within 6 months after the effective date of this amendatory Act of the 96th General Assembly and by paying to the Fund an amount to be determined by the Board, equal to (i) the difference between the amount of employee and employer contributions transferred to the Fund under Section 9-121.17 and the amounts that would have been contributed had such contributions been made at the rates applicable to members of this Fund, plus (ii) interest thereon at the actuarially assumed rate for each year, compounded annually, from the date of service to the date of payment.