Except as otherwise provided in subsections 2 and 3 of NRS 371.040, upon the registration for the first time in this State after the beginning of the period of registration of a vehicle which is registered pursuant to the provisions of NRS 706.801 to 706.861, inclusive, or which has a declared gross weight in excess of 26,000 pounds, the amount of the governmental services tax must be reduced one-twelfth for each month which has elapsed since the beginning of the period of registration.