Fixed number of dashes inside path during resize

I have dashed path defined by PathGeometry like this:

<Path Stretch="Fill"
      StrokeDashArray="20 10"
      Stroke="Black">
      <Path.Data>
        <PathGeometry Figures="M 0,0 M 0.5,0 V 1 M 1,1">
        </PathGeometry>
      </Path.Data>
</Path>

But when I resize the window number of dashes increase due to StrokeDashArray definition. It is possible to set parametric length of dashes and gaps (something like: length is equal to 1/4 of whole path)?

I tried to change ScaleTransform for PathGeometry but it affect whole path and yes I read this question and it is different problem.