computeAvgTotCost       Calculate the cumulative and average annual
                        cost over a single period of time
expandYearlyCosts       Expand cost values per year of the database
                        over relevant periods of impact
getInvaCostVersion      Download and read a specific version of
                        'InvaCost'
invacost                'InvaCost' database
modelCosts              Model the trend of invasive alien species costs
                        over time
plot.invacost.costmodel
                        Plot model predictions of cost trends over time
plot.invacost.costsummary
                        Plot raw cumulated cost of invasive species
                        over different periods of time
prettySummary           Provide a pretty summary of model results
summarizeCosts          Summarize costs of invasions over periods of
                        time
