At first, I thought this image is considering all species and that’s why I was very interested to find out the exact percentage of species that are endangered. But, when I saw the section between 51-100 years I was confused because very few bars reached this stage. So, I questioned the validity of my presumptions and then I realized this graph is displaying only a small subset of all the species. I think this representation¬†would fail if more species are taken into account as the data will be too dense to consider differing width as one of the visual variables.