The interviews for the sample survey of industrial and service firms with 20 or more employees for the year 2005 were conducted between February and March 2006.
The sample consists of 3,231 firms in industry excluding construction and 1,159 non-financial private service firms, representing 8.4 and 4.3 per cent of the total respective reference populations. Because of the bigger sampling fraction of large firms, the two samples represent respectively 28 and 18 per cent of payroll employment in the reference populations, which in turn account for a very substantial share of the sectoral aggregates (which include also firms with fewer than 20 employees), i.e. 81 per cent of both turnover and investments and 68.8 per cent of payroll employment in industry, and 49 per cent of turn over, 55 per cent of investments and 58.3 per cent of payroll employment in the service sector. By over-sampling the largest firms we improve the accuracy of estimates of the totals of the most important aggregates (employment, turnover and investments) and of their fluctuations over a period of time.