step,rule,n_before,n_after,n_removed,rationale
1,drop exact duplicate rows (all 5 columns identical); keep first occurrence,445,400,45,file assembled from several extracts; repeated identical records of the same firm
2,recode revenue to millions USD: USD_thousands values divided by 1000; USD_millions unchanged,400,400,0,revenue reported in mixed units; all outputs must be in millions USD (recode only)
3,drop firms with empty (unknown) revenue: F0048;F0121;F0129;F0269;F0348;F0399,400,394,6,revenue unknown; cannot contribute to revenue aggregates (task rule)