The GHG Protocol Corporate Standard requires setting a base year for comparing emissions over time. To be able to compare over time, the base year emissions must be recalcualted if any structural changes occur in the company. In a deal completed January 2002, the ENDESA Group, a power generation company based in Spain, sold its 87.5 percent holding in Viesgo, a part of its Spanish power generation business, to ENEL, an Italian power company. To account for this structural change, historical emissions from the six power plants included in the sale were no longer accounted for in the Endesa GHG inventory and therefore removed from its base year emissions. This recalcualtion provides ENDESA with a complete and comparable picture of its historical emissions.