Thanks Robert, I was able to download the file. Indeed your data is not dense on time (some months are missing when at this level of filtering, see barchart below.

OAC can handle this but only by defining a time hierarchy in its metadata layer. The direct connection to the db that you currently have with DV is not yet able to handle this case (will be in future release).

So for this to work, a 'Subject Area' needs to be created connecting to your database (either via the metadata Admintool, or the online modeling tool in OAC), within this Subject Area, time will be declared as a time hierarchy, and from this point time series function like period rolling will work with this data.

hope that helps

Philippe