Year current US$ 2000 48.67858491 2001 50.30595311 2002 51.82295263 2003 27.83193351 2004 28.3295796 2005 54.38362932 2006 57.19080345 2007 78.78220686 2008 107.17269866 2009 116.55801097 2010 138.64195907 2011 159.68053074 2012 167.19003087 2013 171.44909278 2014 160.78634089 2015 161.94431397 2016 191.61799121 2017 201.52726845 2018 200.6990248 2019 211.86982308 2020 232.47894565 2021 278.62370128