By contrast any qualitative changes in the work of these wage and salary earner groups, such as the introduction of new duties, the removal of old duties or a rise in educational level, will be reflected in the index. In practice the index measures the av-erage development of earnings for regular working hours in different industries. Earnings are measured for regular working hours only and compensation for overtime, holiday pay and other such items are not included. Data are coded to 52 groups. There are 301 base series in the index of wage and salary earnings, which relate to categories in local occupation classifications.
All occupations are covered, only the highest management category is excluded.
Persons aged below 15 and above 69 years old are excluded. The wages and salaries are covered and total compensation is not covered. The basis for employment is full time. Incentives and overtime pay are excluded. The data given by the central government and municipalities employer organizations are practically total.