Every 5 years. There is no selection of products.
Selected units report all products they produce.
Units with 10 or more employees, registered within NACE Rev. 1, 10-40, are selected from the Business Register and the Statistical Register of Employment. All large units are included. Paper questionnaires by mail. Laspeyres formula is used. To overcome this span every year, linear correction of the base year weights is done using annual indices at the 4-digit level.