This chart shows the trend in sales over time for each salesperson, month by month.
A type of chart well suited to showing changes and trends over time is the Line chart. You could make comparisons of salesperson performance dramatically visible by showing monthly numbers this way.
To do that, you would right-click the border of your chart to select it, and then you would click Chart Type on the shortcut menu. When the Chart Type dialog box opened, you would select a Line chart in the Chart type list.
In this chart you can see how sharply Suyama's sales rose in February before leveling off in March. Both Peacock and Davolio also peaked in February, but they dropped back down in March. You could figure out these trends on other types of charts, but on a line chart they leap to your eye.