McDonald's McCurrency?

McDonald's (NYSE:MCD)recently reported global sales are on an upsurge. Banging the corporate drum they made reference to "Constant Currencies" when referring to global earnings. In the footnotes they provide "Information in constant currency is calculated by translating current year results at prior year average exchange rates." This is not a real number. Imagine looking at ExxonMobils revenues on the basis of last years oil prices. Who cares. Proper analysis needs to be grounded in reality.