§ 54. Exemption from taxation of notes and bonds. It is hereby determined that the creation of the agency is in all respects for the benefit of the people of the state and for the improvement of their health, safety, welfare, comfort and security, and that said purposes are public purposes and that the agency will be performing an essential governmental function in the exercise of the powers conferred upon it by this article. The state covenants with the purchasers and all subsequent holders and transferees of notes and bonds issued by the agency, in consideration of the acceptance of and payment for the notes and bonds, that the notes and bonds of the agency, issued pursuant to this article and the income therefrom and all its fees, charges, gifts, grants, revenues, receipts, and other monies received or to be received, pledged to pay or secure the payment of such notes or bonds shall at all times be free from taxation, except for estate and gift taxes and taxes on transfers.