Year current US$ 2000 117.93763583 2001 117.87628419 2002 134.99979848 2003 145.30402585 2004 154.42052695 2005 173.11705671 2006 183.72566574 2007 207.73132646 2008 234.33815536 2009 188.9329207 2010 165.95831308 2011 177.49514107 2012 197.83497007 2013 190.50117538 2014 194.31573042 2015 187.08229045 2016 187.75171724 2017 194.56626606 2018 195.50795801 2019 194.79392913 2020 164.53323162 2021 191.46786394