(a) If a member employee receives increases in compensation during any three (3) years of service which are not related to promotion and which exceed the average increase received by other employees of the same employer holding comparable positions, the excess shall be excluded when computing the highest average salary if the board finds, after consideration of all circumstances, that the primary purpose of the compensation increase was to increase the retirement benefit of the employee. If there are no employees of the same employer holding comparable positions, the increases may be excluded from the highest average salary if they exceed the average percentage increase received by all other employees of the same employer during the period involved. In making a determination under this section the board may also consider:
072-8 Wyo. Code R. § 8-3