Slight performance optimization in GoalAxis

[stylextv]

After creating this pr, I decided to take a look at the other goals and didn't find much besides this performance tweak. The performance gain is pretty small and I didn't really know if I should even make this change, but decided to anyway. Note: This change (most likely) doesn't affect the result of the calculation, it just makes it faster.

Also, I didn't create an issue first, so I hope it's ok to just create this pr.

[scorbett123]

In fact, it is preferable to just create a pr, it means that there are less issues cluttering my emails, and the issues tab.