Proportion of threatened and extinct species: The graph shows the proportion of threatened species in 19 species groups. The degree of threat is divided into the following categories: ‘Extinct’, ‘Critically Endangered’, ‘Endangered’, ‘Vulnerable’, ‘Near Threatened’ and ‘Least Concern’. In each of the 19 species groups, at least one third of the species are listed on the Red List as threatened or extinct. In some species groups, this share is considerably higher, for example among stoneflies and butterflies.