Billing Records. A record associated with the computation of energy costs billed to an occupant shall be maintained for a period of 2 years. The owner shall maintain the following records: The bills from the utility to the owner for the preceding 24 months; The calculation of the average cost of electricity and gas for each of the preceding 24 months; and The readings of the measuring device in the dwelling unit of the occupant for each of the preceding 24 months. Upon request by an occupant, the owner shall make available for inspection the records maintained under § A(2). The owner shall maintain a record of all measuring devices showing an identification number and its location. The owner shall maintain a record of all written complaints received and copies of the inspection reports prepared under COMAR 20.26.03.