N.D. Cent. Code § 40-45-28

In July of each year, the police pension board may add, if found actuarially sound, a cost of living increase to the monthly amounts paid beneficiaries from the pension fund. The total monthly pension payment under this section shall not exceed sixty percent of the monthly salary average during the preceding thirty-six months for the same or comparable position in the police department as held by the retiree in the retiree's last month before retirement.