A % Area chart is very similar to an Area chart, however, the shaded areas are based on percentages rather than amounts (the Y-axis displays the percentage from 0 to 100% rather than the total amount). See the Area chart page for more information.
% Area charts provide a different way to view the proportional areas. They also have the benefit of tooltips showing the values, which display when you hover over the data points.
Prepare the data in the grid, click the Chart 
button, then click the Line chart category button and select the % Area option.
