175.211  Separation from service; refunds.--If a firefighter leaves the service of the municipality or special fire control district before accumulating aggregate time of 10 years toward retirement and before being eligible to retire under the provisions of this chapter, the firefighter shall be entitled to a refund of all of his or her contributions made to the firefighters' pension trust fund after July 1, 1963, without interest, less any disability benefits paid to him or her after July 1, 1963. If a firefighter who has been in the service of the municipality or special fire control district for at least 10 years and has contributed to the firefighters' pension trust fund for at least 10 years elects to leave his or her accrued contributions in the firefighters' pension trust fund, such firefighter upon attaining the age of 50 years may retire at the actuarial equivalent of the amount of such retirement income otherwise payable to him or her.