Alright, I'm not the one who made the chart so I might be wrong but here's what I understand and how I take it.
We all know that the swing meter (except for putters') is not linear. Take a look at the chart, 100 yards for instance, when you apply 100% of power, it goes 100 yards, not a rocket science, good and simple enough. The chart tells you, however, If you wanna hit it 85 yards, you gotta apply approx. 87.5% of power, not 85%. In other words, if you hit it 85%, it doesn't fly 85 yards but only 81.7 as if you applied only 81.7% of power so you gotta adjust the power % accordingly using the chart.
The author was diligent enough to make it distance by distance from 50 yards to 250, and kind enough to share it with the rest of us. Chapeau!
Anyone is welcome to correct me if I'm wrong.