Article 16 (3) of the First Directive is hereby supplemented by the following subparagraph:
"In the case of the risks listed under No 18 in point A of the Annex, the amount of claims paid used to calculate the second result (claims basis) shall be the costs borne by the undertaking in respect of assistance given. Such costs shall be calculated in accordance with the national provisions of the Member State in whose territory the head office of the undertaking is situated."