When a member cannot obtain documentation of accumulated sick leave because records at the employing school(s) are not available, TRS will calculate an average using the last ten (10) years of employment. The number of days absent each year during the last ten (10) years shall be averaged to determine the average number of sick leave days used each year. The average sick leave used will be subtracted from a standard ten (10) days per school year and the difference multiplied by the total years of creditable Oklahoma membership service.
Okla. Admin. Code § 715:10-5-30