A licensee shall retain all records relating to its purchases, sales and transactions governed by this subpart, including all records necessary to establish the licensee's eligibility, for five years subsequent to the end of the quota year in which such purchases, sales or transactions occurred. During that period, the licensee shall, upon reasonable notice and during ordinary hours of business, grant officials of the U.S. Department of Agriculture full and complete access to the licensee's premises to inspect, audit or copy such records.