The same graph shows that sulphur in gasoline was regulated in 2002. However, it was not sufficiently regulated. Why was there further regulation in 2005? I understand that there was an increase between 2004 and 2005, but sulphur in gasoline was regulated in 2005, and the price of refining went down, it went from 16.3¢ to 16.1¢ due to the regulations, we are told. Here, the regulations are accompanied by a decrease in price...
On June 11th, 2007. See this statement in context.