The appearance properties of an annotation group are not applied to the group's
bounding rectangle, but to its child annotations. However,
child annotation appearance properties have precedence over the group appearance
properties.
The position of a child annotation is always relative to the group's location, and not relative to the entire chart image. "0,0" represents the position of the top-left corner of the group, and "100,100" is the position of the bottom-right corner of the group.
The following properties have no effect when set in a child annotation: IsSizeAlwaysRelative, AnchorDataPoint, AnchorAlignment, AnchorX, AnchorY, AnchorOffsetX, AnchorOffsetY.