Distribution of the observed economic costs of biological invasions in Spain across the autonomous regions (a) relative importance of country, inter-regional and regional levels in costs and number of species with costs (b) proportion of entries (c) total economic costs (US$ million), and (d) number of species with costs. All values correspond to the robust data (reported, incurred and reliable costs); values in (b) and (d) correspond to the raw data and (c) to the expanded data.