Figure 3 from: Maes D, Vanreusel W, Herremans M, Vantieghem P, Brosens D, Gielen K, Beck O, Van Dyck H, Desmet P, Vlinderwerkgroep Natuurpunt (2016) A database on the distribution of butterflies (Lepidoptera) in northern Belgium (Flanders and the Brussels Capital Region). ZooKeys 585: 143-156. https://doi.org/10.3897/zookeys.585.8019

Figure 3 - Number of collected records between 1830 and 1985 (left) and between 1986 and 2014 (right) in the two datasets (INBO and Natuurpunt). Each number on the x-axis stands for a period of 5 years (e.g., 1905 = 1901–1905, 1910 = 1906–1910, etc.). Note the different scales on the y-axis for both figures.