This section display grouped barcharts, stacked barcharts and percent stacked barcharts. This 3 types of barplot variation have the same objective. It displays a numerical value for several entities, organised into groups and subgroups. A grouped barplot
display the subgroups one beside each other, whereas the stacked ones display them on top of each other. The percent variation normalise the data to make in sort the value of each group is 100. It allows the compare the importance of each
subgroups in each group more effectively. Note that faceting can be a good alternative.