1. The board of education is authorized from time to time, in its discretion, to increase the retirement benefits now or hereafter provided pursuant to sections 169.410 to 169.540 and to adopt and implement additional retirement benefits and plans, including without limitation early retirement plans, deferred retirement option plans and cost-of-living adjustments, but excluding compensation to retired members pursuant to section 169.475, and for such purpose the contribution rate of members of the retirement system may be increased to provide part of the cost thereof, subject to the following conditions:

(1) Any such increase in retirement benefits and additional retirement benefits and plans shall be approved by the board of trustees;

(2) The board of trustees shall have presented to the board of education the projected increases in rates of contribution which will be required to be made by members and the board of education to the retirement system to pay the cost of such increases in retirement benefits and additional retirement benefits and plans; and

(3) Any increase in the contribution rate of members of the retirement system shall be approved by the board of trustees and shall be deducted from the compensation of each member by the employing board and transferred and credited to the individual account of each member from whose compensation the deduction was made, and shall be administered in accordance with sections 169.410 to 169.540; provided that, any such increase in the members’ contribution rate shall not exceed one-half of one percent of compensation in any year for such increases to retirement benefits and additional retirement benefits and plans adopted during such year by the board of education pursuant to this section, and all such increases in the members’ contribution rate shall, in the aggregate, not exceed two percent of compensation.

2. The board of trustees is authorized from time to time, in its discretion, to increase the retirement benefits, now or hereinafter provided under sections 169.410 to 169.540, and to adopt and implement additional retirement benefits for persons who have retired, including cost-of-living adjustments, provided that the board of trustees finds the additional benefit will not require an increase in the contribution rate required by the members, will not increase the contribution required from the board of education, and is actuarially sound. In the event the board of trustees authorizes an increase under this section, it shall certify in writing to the board of education the findings, including but not limited to all actuarial assumptions, upon which the board of trustees determined that the increase in benefits would result in no increase in contributions by members or the board of education.