Provided, however, that with respect to business written prior to January 1, 1980, the Commissioner shall not require the filing of such supporting data which has not been required to be recorded under statistical plans approved by the Commissioner.
Provided, however, that no filing may be returned or disapproved on the grounds that such information has not been furnished if insurers have not been required to collect such information pursuant to statistical plans or programs or to report such information to the Bureau or to statistical agents, except where the Commissioner has given reasonable prior notice to the insurers to begin collecting and reporting such information, or except when the information is readily available to the insurers.
N.C. Gen. Stat. § 58-36-15