Vehicles in Austria are subject to two different types of taxes: a fuel consumption tax (Normverbrauchsabgabe/NoVA)) and a car registration tax (Kraftfahrzeugsteuer). The fuel consumption tax NoVa was introduced in 1992. This tax has to be paid at the time of purchasing a new car and is based on the fuel consumption specifications of the car. The Structural Adjustment Act in 1996 led to an increase in this tax rate of about 1% by changing the way fuel consumption is measured. At the same time, the maximum tax rate was raised from 14% to 16%. Since the fuel consumption tax increases the tax burden depending on the vehicle's relative fuel consumption, this measure offers incentives for the purchase of energy-efficient vehicles. In recent years a strong trend towards diesel powered vehicles reduced the average fuel consumption. In 1996 diesel powered vehicles accounted for 50% of all new registrations compared to 22% before the introduction of the fuel consumption levy. Diesel vehicles currently hold a share of 40% to 50% of the total passenger vehicle fleet compared to 5% in the mid-1980s. The car registration tax has to be paid for each month in which a vehicle is registered and has a number-plate, the prerequisite to use public roads. The level of the tax depends on engine specification and it is paid to the insurance company together with the liability insurance premiums. The tax is then forwarded by the insurance company to the tax authority.