North Dakota Constitution Art. XV, § 3

The limitations established by this article shall have prospective effect only, and service as a member of the house of representatives, service as a member of the senate, and prior election to the office of governor shall not be counted against any service or election, respectively, of any individual that occurs after the effective date of this amendment. Service by the lieutenant governor in his capacity as president of the senate shall not count toward the cumulative amount of time an individual may serve as a member of the senate.