Additionally, output data are collected from special studies on the work in progress of the livestock sector and on the size of the growing crops and their costs of production. The quarterly survey covers all state and statutory farms, twice per year are surveyed household farms based on sample survey. Also used in the quarterly calculations are the comprehensive annual data, collected by the Ministry of Agriculture, on the country's stock of land and its use and on the income and expenditure, capital stock and inventories of agricultural units. The Ministry also collects the annual data on the number of trees felled and the area covered by forests. The survey covers all actually active enterprises registered in the Statistical Business register and, in general, has a response rate exceeding 90 percent.
Intermediate consumption is calculated using ratio from annual surveys from previous.
For unincorporated enterprises data are adjusted. For storage and communication sectors, the main source of output data is the quarterly survey of such businesses. The estimates for dwelling services are derived from the quarterly survey of the rented-out housing stock and rents. The survey covers around 4000 households every year in major cities, smaller towns and rural areas with a response rate of about 80 percent, which is around 340 responses per month. The survey relies on random sampling methods based on the Population Register and on the households' list maintained by the rural administrative units.