Fig. 2
From: Unveiling the hidden economic toll of biological invasions in the European Union
a Temporal trend of highly reliable, observed average annual costs per decade (solid bars) with (blue) and without (orange) extreme values recorded in InvaCost for European Union member states (annual costs are presented on the log10 scale). Points are annual totals, and the dash-dot line is the overall annual average. b Diagnostic plots showing changes in the total annual cost (highly reliable, observed subset) over time (considered against impact year that refers to the year that the cost incurred). Red: periods of non-random declines. Blue: periods of non-random increases