score:2
Wikipedia to the rescue (At least possibly)
The types of tax that were next in importance were the real and personal property taxes like the verponding, a kind of rates. This amounted to 8.5 percent (the Twelfth Penny) of the rental value of all real property. Wikipedia
Having said that, google produces multiple entries for the term "twelfth penny" tax - most of them have to do with France, and the few that have to do with the Netherlands are quotes from the works of Thomas Carlyle which are not relevant.
If I'm correct, the law was the verpondering.