Dear Timoteo Jazul, Thank you for visiting the KOSIS website. As you know, monthly, quarterly and annual data of the Economically Active Population Survey (EAPS) were retrospectively revised for time series data between July 2000 and December 2017. According to the revision of the 10th Korea Standard Industrial Classification, time series data from 2013 were retrospectively revised. According to the revision of the 7th Korea Standard Occupational Classification, time series data from 2013 were retrospectively revised. For example, the results of the EAPS in December 2017 were firstly released on January 10th, 2018. Then the revised results of the EAPS in December 2017 were released on February 14th, 2018. These two data sets are different. Accordingly, data revisions may slightly affect the comparability of time series data. For your reference, considering the seasonality of raw data, it is recommended to check year-on-year percent changes in employment trends instead of month-on-month percent changes. Seasonally adjusted figures enable users to compare month-on-month percent changes. In the meantime, every February, revised seasonal adjustment factors are applied to data of the previous 1 year regardless of the calibration of time series data. Thank you.