Here is a study conducted by CRAFT on the poor effeciency we were getting with our keggle system.

Fred
Fred, great research. It actually agrees with the numbers I've been getting on my cooler tuns.
BTW:
For 1.100 I repeatedly get 55%
For 1.110 I repeatedly get 44%.
Both at a 1.25 ratio, because that's as low as I want to go.
Just one small bone to pick on charting practices.
The Independent axis is the X or horizontal.
The Dependent axis is the Y or vertical.
General practice also dictates the origin (juncture of X and Y axis) to be the lowest value, which you have done.
You are plugging in gravity ( independent, or chosen variable) and charting the efficiency found ( dependent or the result of experimentation) hence the axes are reversed in the posting.
It just makes understanding you excellent work easier.