Year current US$ 2000 62.07320558 2001 62.61004619 2002 70.03865368 2003 82.6826019 2004 100.38481287 2005 92.52274702 2006 91.14421736 2007 95.76533714 2008 110.29644509 2009 114.20498852 2010 157.59351817 2011 158.65902799 2012 172.09820166 2013 183.97980584 2014 245.37479121 2015 214.78446037 2016 237.99213061 2017 262.06964432 2018 282.231918 2019 316.05713432 2020 292.49129889 2021 277.91561825