The index of turnover of trade describes development in the turnover of enterprises engaged in trade. Turnover for the largest enterprises in their respective industries is described with the data collected with the sales inquiry while the data on sales obtained from periodic tax returns are exploited to describe the turnover of other enterprises. Turnover is exclusive of value-added tax. In addition, the volume index of retail trade sales, from which the impact of prices has been eliminated, is produced on trade. The calculation is based on estimation of change. Sums by industry are calculated with data on the enterprises for which comparable data on turnover are available for both the examined month and the corresponding month of the previous year. The obtained sums are used to calculate annual changes by industry. Because preliminary data can only be calculated from the data Statistics Finland has obtained by inquiring enterprises direct, their calculation is based purely on the estimation of change, whereas the impact of enterprise openings and closures on the produced indices is also taken into account in the calculation of revised data. The annual changes thus obtained are used to raise the turnover index of the corresponding month of the previous year. The latest index figures may become slightly revised as new data accumulate and enterprises report changes to their data. Due to supplementations, the data will become updated in releases for over twelve months. The statistics and indices compiled from the data are public under the condition that no individual enterprise’s data can be identified from them. Indicators of turnover are also published for sub-industries in construction, other services and manufacturing. Data on the turnover and export turnover of other industries, enterprise groups and areas can also be produced to order as special compilations.