Almindelig (≥1/ 100, < 1/ 10); ikke almindelig (≥1/ 1000 og < 1/ 100); sjælden (≥1/ 10. 000 og < 1/ 1000); meget sjælden (≤1/ 10. 000).
Estimated frequencies of events are ranked according to the following convention: common (≥ 1/ 100, < 1/ 10); uncommon (≥ 1/ 1,000 < 1/ 100); rare (≥ 1/ 10,00, < 1/ 1,000); very rare (≤ 1/ 10,000).