If that was a Shook, it would be closer to 200%, I think. I am aware of how low you can take a vented and understand the aerodynamics that cause the phenomenon. Just saying it's a lot of air space. There's a point at which the reduced weight no longer has as much of an effect because of the reduced turbulence on the back of the sail. The effect begins to taper off once the venting exceeds 50% of the sail area, and I believe, without actually doing the math, that you're at between 65% and 75% air space.