New York has the largest hybrid bus fleet in the country, and some of the first hybrid taxis. A large percentage of the city-owned vehicle fleet, including the personal cars of top city officials, are required since 2005 to be fuel efficient hybrid vehicles like the Toyota Prius or Honda Accord gas-electric sedan that produce minimal particulates and carbon dioxide emissions. In 2005 the city's vehicle fleet had 6,000 alternative fuel and 70 electric vehicles. A biodiesel processing plant will soon open in Brooklyn that will process of biodiesel a year and distribute it to conventional gas stations in the city.