Year current US$ 2000 64.09311151 2001 83.37766062 2002 88.94615568 2003 86.89922177 2004 88.05054548 2005 93.76015989 2006 108.76504947 2007 136.42510385 2008 165.72872913 2009 155.55213836 2010 161.47706609 2011 165.66773964 2012 162.34816234 2013 172.51472711 2014 184.20695787 2015 193.25900392 2016 204.3213449 2017 194.5283445 2018 196.69799545 2019 204.39003714 2020 197.38436723 2021 213.44393997