The Pie Chart is similar to the Doughnut Chart which demonstrates a set of data which comprise a logical unit. This data shows the distrution of a subset of data which makes up a whole. In this example we can see the "pie pieces" vary in size according to the total value for each record.
The Pie Chart is intended to show the distribution of data for records that comprise one whole logical unit. In this case we are showing the distrubution of sales for the 2015 calendar year.
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