Meget almindelig (≥1/ 10, almindelig (≥1/ 100 til < 1/ 10), ikke almindelig (≥1/ 1. 000 til < 1/ 100), sjælden (≥1/ 10. 000 til < 1/ 1. 000), meget sjælden (< 1/ 10. 000), ikke kendt (kan ikke estimeres ud fra forhåndenværende data).
Frequency categories are defined according to the following convention: very common (≥ 1/ 10), common (≥ 1/ 100 to < 1/ 10), uncommon (≥ 1/ 1,000 to < 1/ 100), rare (≥ 1/ 10,000 to < 1/ 1,000), very rare (< 1/ 10,000), not known (cannot be calculated from the available data).