of India. In India, most CNG vehicles are dual-fuelled, which means they can run both on CNG and petrol. This makes it very convenient, and users can drive long distances without worrying about the availability of natural gas (as long as petrol is available). As of December 2010, India had 1,080,000 NGVs and 560 fueling stations, many of the older ones being LPG rather than CNG. In addition, it is thought that more illegally converted LPG autos than legal ones ply the streets in India, some estimates are as high as 15 million "autos" (running the gamut of everything from LPG motored pedal bicycles to CNG buses) In 1995, a lawyer filed a case with the Supreme Court of India under the Public Interest Litigation rule, which is part of the Constitution of India and enables any citizen to address the Supreme Court directly. The lawyer's case was about the health risks caused by air pollution emitted from road vehicles. The Supreme Court decided that cars in circulation after 1995 would have to run on unleaded fuel. By 1998, India was converted to 100% of unleaded fuel after the government ruled that diesel cars in India were restricted to 10,000 ppm after 1995. At the beginning of 2005, 10,300 CNG busses, 55,000 CNG three-wheelers taxis, 5,000 CNG minibuses, 10,000 CNG taxis and 10,000 CNG cars run on India's roads (1982-2008 Product-Life Institute, Geneva). The Delhi Transport Corporation currently operates the world's largest fleet of CNG buses for public transport. Currently India stands third with 3.045 million NGVs. Iran By the end of 2015, Iran had the world's largest fleet of NGV at 3.5 million vehicles. The share of compressed natural gas in the national fuel basket is more than 23%. CNG consumption by Iran's transportation sector is around 20 million cubic meters per day. There are 2,335 CNG stations. The growth of NGV market in Iran has in large part been due to Iranian government intervention to decrease the society's dependence on gasoline. This governmental plan was implemented to reduce the effect of sanctions on Iran and make the nation's domestic market less dependent on imported gasoline. Iran has been manufacturing its own NGV's through local manufacturing using dedicated CNG engines which use gasoline only as a backup fuel. Also by 2012, Iranian manufacturers had the capacity to build 1.5 million CNG cylinders per year and therefore Iranian government has