Pareto charts combine a single series column chart with a line chart. Columns are first sorted in a descending order. The line shows the cummulative value of the columns, as a precent.
Our US Sales demo charts show columns with US product quantities sold for 5 years, between 2003 and 2007. Values are first sorted in a descending order (this is how 2004 appears first). A separate line chart is added on top, to show the cumulative percentual value up to 100%.