It's long since been discussed that the Dunmer do not pay taxes. Every time I asked where the information came from I was led to the http://www.uesp.net/wiki/Skyrim:Decree_of_Monument displayed on Refugee's Rest. If there are any other sources, please inform me. However, Dragonborn revealed that the promise of the Jarls to the Dunmer people was not to those who would make their homes in Windhelm, but it was part of http://www.uesp.net/wiki/Dragonborn:Loading_Screens
The loading screen from the wiki:
"Untithed to any thane or hold, and self-governed, with free worship, with no compensation to Skyrim or the Empire except as writ in the Armistice of old wheresoever those might still apply, and henceforth let no Man or Mer say that the Sons and Daughters of Kyne are without mercy or honor." -Skyrim's Offer of Solstheim to Morrowind, 4E 16
So what does this mean? Are there any other sources saying the Dunmer do not pay taxes? If not, then the only one we thought we had was not.