That said, "[t]he burden is upon the party asserting that the opposite party could have lessened his damages, and such proof must include sufficient data to allow the jury to reasonably estimate how much the damages could have been mitigated." Georgia Farm Bureau Mut. Ins. Co. v. Turpin, 668 S.E.2d 518, 521 (Ga. Ct. App. 2008) (internal citation omitted). Defendant has not met that burden.