(a) A member's final average salary shall be the average wages earned by such a member during any five consecutive years of New York State service credit which provide the highest average wage; provided, however, if the wages earned during any year included in the period used to determine final average salary exceeds that of the average of the previous four years by more than 10 percent, the amount in excess of 10 percent shall be excluded form the computation of final average salary. Where the period used to determine final average salary is the period which immediately precedes the date of retirement, any month or months (not in excess of 12) which would otherwise be included in computing final average salary, but during which the member was on authorized leave of absence at partial pay or without pay shall be excluded from the computation of final average salary and the month or an equal number of months immediately preceding such period shall be substituted in lieu thereof.

(b) Wages shall mean regular compensation earned by and paid to a member by a public employer. Wages paid during a school year in excess of the annual salary paid to the Governor pursuant to section three of article IV of the New York Constitution and wages paid by any one or more employers other than the two employers paying the highest wages during a school year shall be excluded from the calculation of the member's final average salary.