Each folder contains files of either level of percent change data. The prefixes are either "level" or "pchg" to indicate the transformation. 
If the prefix is "pchg", the suffix of the filename will indicate the type of growth (either 1 quarter growth or 4 quarter growth).
These files either consist of vintages (multiple columns) or are realized, advance values (only one column), indicated by "vintages" or "realized_advance", respectively.