Section 2046-O. Tax contract

The state covenants with the purchasers and
  with all subsequent holders and transferees of bonds or notes issued  by
  the agency pursuant to this title, in consideration of the acceptance of
  and  payment  for  the  bonds  or  notes that the bonds and notes of the
  agency issued pursuant to this title and the income therefrom,  and  all
  moneys,  funds and revenues pledged to pay or secure the payment of such
  bonds or notes, shall at all times, be free  from  taxation  except  for
  estate and gift taxes and taxes on transfers.