duction since 2011. The data compilation and presentation methods been published based on seasonally adjusted index numbers. Since 2017, seasonal adjustments for production data have been made us- ing the TRAMO/SEATs method in the JDemetra+ software. A similar approach is used for sub-annual trade data since 2025. The purpose effects within time series. The individual parameters of the seasonal visions, normally at the beginning of each new reference year. Major economic uncertainties or other unusual events, such as the global pandemic of 2020, require frequent reviews of the underlying models based on the most recent available information.