Year current US$ 2000 115.37317079 2001 129.91026847 2002 126.86774474 2003 142.12920565 2004 144.91366501 2005 173.07414966 2006 200.9130664 2007 231.44676582 2008 220.5583561 2009 153.40751387 2010 177.95152057 2011 184.01892997 2012 201.70175879 2013 196.84283083 2014 208.42443591 2015 184.632458 2016 223.59975487 2017 208.68883727 2018 201.07239926 2019 194.49540733 2020 192.35849285 2021 176.90309908