1. The required solvency margin shall be determined on the basis either of the annual amount of premiums or contributions, or of the average burden of claims for the past three financial years.
In the case, however, of insurance undertakings which essentially underwrite only one or more of the risks of credit, storm, hail or frost, the last seven financial years shall be taken as the reference period for the average burden of claims.
2. Subject to Article 17, the amount of the required solvency margin shall be equal to the higher of the two results as set out in paragraphs 3 and 4.
3. The premium basis shall be calculated using the higher of gross written premiums or contributions as calculated below, and gross earned premiums or contributions.
Premiums or contributions in respect of the classes 11, 12 and 13 listed in point A of the Annex shall be increased by 50%.
The premiums or contributions (inclusive of charges ancillary to premiums or contributions) due in respect of direct