Social insurance costs were introduced as a compulsory payment to the social insurance budget; at the same time a definite category of the population was offered the option of making contribution payments for pension insurance on voluntary basis.
社会保险费被引入，作为一种必须向社会保险预算缴纳的费用；与此同时，向明确的人口类别提供了在自愿基础上支付养恤金保险缴款的选择。