When the x-axis is moved to the top, the area chart shows only one record or appears monochromatic.
When the x-axis is placed at the top of the chart, the area polygons of the displayed data are drawn by stacking up the polygons from smallest to largest. Thus, the last polygon drawn, which is the largest polygon, draws over the top of all previously drawn polygons. This makes the chart appear either to be monochromatic or to contain only one record.
Display the area chart with the x-axis below the y-axis.
Displaying the area chart with the x-axis on the bottom draws the polygons in the correct order, from largest to smallest.