Progress column charts compare two series' values: they show how much one series values are, compared with another series. Last background series columns are always at 100%, while the front series columns show the percent of their values, compared with the back series. Such charts may also show the fraction a series action was completed, compared to another series.
Our UK vs US Sales Progress demo charts show the percent of UK sales (as product quantities), compared to the US sales (always at 100%), in the same three different years: 2007, 2008 and 2009. The multiple series are the US and UK countries. Remark the horizontal X axis is a category axis: year values are distributed at equal intervals on the axis. Quantity value columns for each year are displayed one within the other for each country, with a containment visual effect. It's like each US column contains a UK column. All columns for a specific country have a different distinct color: US columns use the first palette color, and UK columns the second palette color.