Section 1. An incorporated city or town that institutes after August 31, 1981, by charter, ordinance, or statute a program of continuing service retirement, disability retirement, or death benefits for any of its officers or employees shall require participating officers and employees to contribute a percentage of their salaries to the program during each payroll period. The city or town also shall make contributions to the program during each payroll period. The ratio of municipal contributions to the aggregate contributions of officers and employees may not be less than one to one or more than two to one.