Changes in the volume of the physical output of the nation's factories, mines and utilities are measured by the index of industrial production. The figure is calculated as a weighted aggregate of goods and reported in headlines as a percent change from previous months. It is often adjusted by season or weather conditions and thus volatile. However, it is used as a leading indicator and helps in forecasting GDP changes.
Former the industrial output data was based on all main sectors of industry, from January 2003 Goskomstat started to release data on industrial output based on three sectors: mining, manufacturing and production and supply of electrical energy, gas and water, on the basis of production of 730 representative goods from these branches.