The interviews for the sample survey of industrial and service firms with 20 employees and over for the year 2007 were conducted in February and April 2008.
The sample consists of 2,980 industrial firms, excluding construction, 465 construction companies and 1,083 non-financial private service firms, representing 8.1, 6.5 and 3.8 per cent of the respective total reference populations. Because of the bigger sampling fraction of large firms, the three samples respectively account for 28.3, 20.4 and 18.5 per cent of payroll employment in the reference populations, which in turn represent a very substantial share of the sectoral aggregates.
