Except as otherwise provided in NRS 319.169 and 319.500, the Division may invest its money in collateralized mortgage obligations or in trusts created to finance, acquire or invest in collateralized mortgage obligations if the collateralized mortgage obligations or trusts so created are:
1. In furtherance of the purposes of the Division; and
2. Rated within one of the top three rating categories of a national rating service at the time the investment is made.