15%, 4 Perimeter layers
The monitorHeadsetMount I printed upside down to minimize the amount of supports. You still need some supports underneath the hook part but otherwise this orientation does really well, even the threads. Another advantage of this orientation is it puts the layers in the same direction of the force when mounted so you don't have to worry about the layers splitting and the part breaking.
The monitorHeadsetScrew prints pretty well on either the top or bottom faces.