I am afraid it is not possible to estimate the measurements as percentages to one another. The way we treat measurements is different to many other drafting methods. Lekala and Sewist are based on a database of actual anthropometric measurements, and for each set of leading measurements the system finds a set of these measurements as implied for a figure with normal posture. The full description is available here: http://www.sewist.com/pages/sizeguide

The corrections to these measurements as suggested on the website imply that the corresponding anthropometric landmarks are slightly moved, and the whole set is re-calculated. Unfortunately there's no way right now to show a full set of these, and actually this might be even overwhelming. It is rather how you feel about your measurements subjectively, e.g. I have rather long arms and the sleeves of a dress sewn on the basis of our free pattern would be a bit short. We always advise to try the free patterns first and see how applying corrections affects the pattern, or getting a free preview for free and paid patterns that would let you estimate how the contours are changed.

By the way you can also get a "comparison" of any two patterns, this is a preview where two patterns are shown one on top of the other. Hope this helps!