Section 11A. Investments shall be valued in accordance with the published valuation standards of the National Association of Insurance Commissioners and in accordance with accounting practices and procedures prescribed or allowed by the commissioner. The commissioner shall require that the value of the investments be computed in accordance with the Accounting Practices and Procedures Manual and the Purposes and Procedures Manual of the Securities Valuation Office of the National Association of Insurance Commissioners, unless modified by the commissioner as the commissioner considers appropriate.