In Mail Boxes, etc. v. Industrial Commission, 181 Ariz. 119, 123, 888 P.2d 777, 781 (1995), the Arizona Supreme Court held that "the best way to measure the lost earning capacity of a sole proprietor is by the market value of the services performed." 181 Ariz. at 122-23, 888 P.2d at 780-81. Mail Boxes was a case in which a sole proprietor had no net earnings, or profits. The court of appeals held that because there was no "earned income" in the business, there was no actual wage attributable to the owner. Id. at 121, 888 P.2d at 779. The Arizona Supreme Court rejected that proposition. Id. at 121-23, 888 P.2d at 779-81. Whether there was profit or not, a market value for the services rendered by the sole proprietor should be determined. Id. In Mail Boxes, the claimant did "not have past wages with which to determine his loss of earning capacity." Id.