What is considered substantial success when it comes to calculating the proportion of substantial success?

In Fotheringham v. Fotheringham, 2001 BCSC 1321, Bouck J. held at para. 45: ... The words “substantial success” are not defined. For want of a better measure, since success, a passing grade, is around 50% or better, substantial success is about 75% or better. That does not mean a court must descend into a meticulous mathematical examination of the matters in dispute and assign a percentage to each matter. Rather, it is meant to serve as a rough and ready guide would look at all the dispute matters globally.