Year current US$ 2006 394000000 2007 453000000 2008 459000000 2009 407000000 2010 417000000 2011 326000000 2012 327000000 2013 322000000 2014 378000000 2015 363000000 2016 373000000 2017 369000000 2018 334000000 2019 342000000 2020 212000000