You want three figures as pseudocoded below:
If Savings < Goal Then
SavingsToGoal = (Savings / Goal) * 100
RemainingToGoal = 100 - SavingsToGoal
AmountExceedingGoal = 0
Else
SavingsToGoal = 100
RemainingToGoal = 0
AmountExceedingGoal = ((Savings - Goal) / Goal) * 100
End If
By the way "Savings to Date" should probably be called "Savings to Goal" because if the saving exceed the goal then the actual saving to date are the goal (green to 100%) plus the excess (purple).