The Line chart is the most basic of our options when it comes to looking at data over time. The Area chart and Stacked Area chart are based on the line chart; the difference is that the area between the axis and the line is filled in with colors to show volume. Because of this, we will focus on the Line chart for our example. Since we have a very nice Date hierarchy, we will use this alongside a couple of measures to see trending. 

Let's look at, setting up the visual:

1. Select the Line chart visual and move it to take up a qaurter of the report canvas.
2. The axis is where we dictate our time category and, for this example, we will use the built-in Date hierarchy by selecting the Date field from the Date(Order) table.
3. We will be using this chart to compare two different measures over time; they will be the Total Sales and Prior Year Sales measures. Select both of these, and they should populate under the Values section.

4. To make it a bit more of an exciting visual, let's take advantage of the hierarchy and it expand it down two levels to include the quarter and month, as seen in Figure 5-14:

With this Line chart, we can clearly see there was a large growth in sales between 2007 and 2008. Visuals that focus on Trend Data can very easily illustrate any outliers, which can allow users to further investigate the cause for the seen trend. This visual can also benefit from some of the formatting options we have talked about previously, such as Data Labels.