I have just been assuming 25% as a ballpark figure. The damages award is so low that even if it's 20% or 30% it won't make much of a difference.
What would is if Lamberth grants pre-judgment interest. Since Delaware court precedent says it is granted as a matter of right, I don't see how Lamberth can weasel out of granting it. But if anyone can find a way it's him.