How to Track Stats
There are three methods you can track stats:
Double-click on the selected stat to add/remove it from displaying on the Data Graph View.
Drag-and-drop it from the Stats/Groups Window into the Data Graph View (see the image below).
Drag-and-drop it from the Event Graph View.
If a stat is being tracked, it will be displayed in a different color and with an "*" symbol next to the name.
Also, you can see how many stats are being tracked in a group by looking at the second number in the () following the Group Name.
The image above for Audio, there are 11 items in the group, 1 of which is currently being tracked.