On the top right side of the report page, there is a tool bar:
When clicked, the second, third, and fourth icons will open your reported data into a bar chart, line chart or pie chart, respectively
Here’s an example of a graphed report
On the right, you can manipulate the graph with the following options:
In order to create a pie chart, you will need to select one person in the report and as many assignments as you’d like.
Your pie chart will then look like this: