(a) For a policy providing mortgage pool insurance issued prior to January 11, 1995, there shall be no additions to or substitutions in a pool of mortgages after one year following the issuance of the policy.

(b) For a policy providing mortgage pool insurance issued on or after January 11, 1995, there shall be no additions to or substitutions in a pool of mortgages after two years following the issuance of the policy.