Section 12. The commissioner shall each year compute the reserve required of liability companies for outstanding losses under insurance against loss or damage from accident to or injuries suffered by an employee or other person, for which the insured is liable, in accordance with accounting practices and procedures prescribed or allowed by the commissioner. The commissioner shall require that value of the reserves be computed in accordance with the Accounting Practices and Procedures Manual of the National Association of Insurance Commissioners, unless modified by the commissioner as the commissioner considers appropriate.