Crude oil import prices come from the IEA's Crude Oil Import Register and are influenced not only by traditional movements of supply and demand, but also by other factors such as geopolitics. Information is collected from national agencies according to the type of crude oil, by geographic origin and by quality of crude. Average prices are obtained by dividing value by volume as recorded by customs administrations for each tariff position. Values are recorded at the time of import and include cost, insurance and freight, but exclude import duties. The nominal crude oil spot price from 2003 to 2011 is for Dubai and from 1970 to 2002 for Arabian Light. This indicator is measured in USD per barrel of oil. The real price was calculated using the deflator for GDP at market prices and rebased with reference year 1970 = 100.