The records shall be accompanied by an affidavit of a custodian stating in substance: (a) That the affiant is a duly authorized custodian of the records and has authority to certify said records, (b) that the copy is a true copy of all the records described in the subpoena, (c) that the records were prepared by the personnel of the hospital, staff physicians, or persons acting under the control of either, in the ordinary course of hospital business at or near the time of the act, condition or event reported therein, and (d) certifying the amount of the reasonable charges of the hospital for furnishing such copies of the record. If the hospital has none of the records described, or only part thereof, the custodian shall so state in the affidavit and file the affidavit and such records as are available in the manner described in sections four-b and four-c. The filing of such affidavit with respect to reasonable charges shall be sufficient proof of such expense, which shall be taxed as costs of court.