4. In the cases referred to in points (a) and (c) of paragraph 2, the total charges shall be calculated in accordance with objective, transparent and verifiable criteria. Such criteria shall be laid down by Member States.
The total income from supplying and allowing the re-use of documents over the appropriate accounting period shall not exceed the cost of their collection, production, reproduction, dissemination and data storage, together with a reasonable return on investment, and — where applicable — the anonymisation of personal data and measures taken to protect commercially confidential information.
Charges shall be calculated in accordance with the applicable accounting principles.