Sets the default for whether the average value of analog tags is plotted on the graph on the Historical Data Viewer.
If set to 1 (default), then the average values for analog tags will be displayed.
Properties for individual pens may be set using the Pen Properties dialog, available in the legend.
Section: System
Default: HDVAnalogPenAverageVisibility = 1
*No restart required (Settings.Dynamic property)
