The survey covers persons insured with the Social Insurance Institution (ZUS) under the title of their employment in all entities of the national economy. The units of statistical analysis and the units of observation are individual paid employment jobs (i.e. in the case of persons with more than one paid employment job, each is considered separately). Wages and salaries include monetary payments (or the monetary value of benefits in kind or their equivalents) under the title of an employment relationship or a service relationship to employees, constituting expenditure incurred by employers to pay for work performed, regardless of their sources of financing, which are included in the contribution assessment basis for social insurance and/or health insurance. Wages and salaries also include payments under contracts of mandate, contracts to perform a specified task and agency agreements if these contracts were concluded with the same employer or to the benefit of the same employer with whom a given person is employed on the basis of an employment relationship. The data presented relates to wages and salaries paid in a given month. Data by place of residence for Poland in total also cover persons residing outside Poland for whom the seat of the main job is in Poland.