如何对齐UIBezierPath圆圈破折号

I am trying to draw a compass using UIBezierPath and adding dashes to the line to mark North, South, East, West directions and points in between. The dashes seem offset (they're not aligned), particularly in the North and South directions and the way I am doing it seems to add an extra dash when the path is closing.I am trying to draw a compass using UIBezierPat