The data from the base dialects used to compare regiolects is all in the 
zip file, where the base varieties are identified in nlbel.lbl, e.g.,

1	"Aalsmeer NH"
etc.

the regiolectal (and standard) pronunciations are all in lijst_GTRP.

If you just need the regiolectal pronunciations, you can just take
this file, which is identical to Regionale-Uitspraken-XSAMPA.txt in this 
directory (and thus available directly, too).

The coding is like X-SAMPA and it's explained in 
     transcriptions-reg-pron-readme.pdf