RectangleAnnotation Text Position

Hello!

is there a way to stick the RectangleAnnotation text on the top of the plotarea? 

i mean like with a LineAnnotation the text will allways be visible even when i zoom in or out. the text sticks on the top.

my problem is that i wanna use a RectangleAnnotation but a text is conected with a DataPoint

new OxyPlot.Annotations.RectangleAnnotation { TextPosition = new OxyPlot.DataPoint(start + (end-start)/2, getMinMaxValue()[1] * 0.95), MinimumX = start, MaximumX = end, TextRotation = -90, Text = title, Fill = OxyColor.FromAColor(50, OxyColor.FromRgb(0, 102,153)), Stroke = OxyColor.FromRgb(0, 102, 153), StrokeThickness = 1 });

and when i zoom in the text isn´t visible anymore...

has anyone an idea? would be nice