These suspensions may be revoked or amended in accordance with § 310.7. No revocation of the suspension provided in § 320.2 will curtail operations of particular carriers existing at the time of the revocation to a level of operations (in dollar or volume terms, whichever is larger) lower than that antedating the revocation in a particular market served prior to the revocation. Should the suspension referred to in § 320.2 be revoked, carriers, as a condition to continuing operations under this section, will be required to provide reasonably complete and accurate data to support estimates of past operating levels in particular markets.