Mosaic plot showing the discovery groups and grades in a visual representation of a contingency table. The width of the stacked boxes represents the fraction of each grade in the sample, while the height represents the proportion per discovery group. All the grades were assigned by three members of the science team (EOG, SK, CC) after consensus following the individual evaluations. In the discovery group, there is a higher fraction of C grades than A grades. In the rediscovery group, there is a higher fraction of A grades than both Β and C grades. Hence, the mosaic plot indicates that, overall, our grading scheme is rather conservative towards newly discovered lenses.