Rising oil prices in recent years meant that ethanol production costs became cheaper than world oil prices after 2004. Flexible fuel engines have been highly successful, reaching 81 per cent of the light-vehicle registrations by 2008 (Brazil, Associagao Nacional dos Fabricantes de Vefculos Automotores, 2008). In this context, it should be noted that, in January 2009, gasoline prices were again lower than ethanol production costs owing to the global recession, but this had again been reversed by January 2011. In 2007, the United States Congress passed a bill that mandated the production of 140 billion litres of corn ethanol by 2022, which would be equal to about 13 per cent of United States gasoline demand.