In the event the balance of the fund remaining after all allocations have been made with respect to all retirement income in a preceding group is insufficient to allocate the full actuarial equivalent of such retirement income to all persons in the group for which it is then being applied, such balance of the fund shall be allocated to each person in such group in the proportion which the actuarial equivalent of the retirement income allocable to him pursuant to such group bears to the total actuarial equivalent of the retirement income so allocable to all persons in such group.
Provided no discrimination in value results, the Board of Trustees shall distribute the amounts so allocated in one of the following manners as the Board of Trustees in their discretion may determine:
Okla. Stat. tit. 74, § 912.1