Most of these taxes are based on energy consumption: 73% of tax revenues come from an oil duty, 15% from the motor vehicle tax and 11% from the electricity tax. With the sharp decline in energy intensity since 1990 and the increase in energy prices, environmental taxes declined as a share of GDP and are now standing close to the OECD average (Figure 4). In 2009, environmental tax revenues accounted for 2.3% of GDP and 6% of total tax revenues.