The annual membership fees for active members shall be payable on or before February 1st of each year. The board of governors may establish the amount of such annual membership fee to be effective each year: PROVIDED, That written notice of any proposed increase in membership fee shall be sent to active members not less than sixty days prior to the effective date of such increase: PROVIDED FURTHER, That the board of governors may establish the fee at a reduced rate for those who have been active members for less than five years in this state or elsewhere.