The reserves for outstanding losses and loss expenses under policies of personal injury liability insurance and under policies of employer's liability insurance shall be computed as follows:

(1) The reserves for outstanding losses and loss expenses under policies of personal injury liability insurance and under policies of employer's liability insurance shall be computed in accordance with accepted loss-reserving standards and principles and shall make a reasonable provision for all unpaid loss and loss expense obligations of the insurer under the terms of such policies.

(2) Reserves under liability policies written during the three years immediately preceding the date of determination shall include any additional reserves required by the annual statement instructions of the national association of insurance commissioners.