Year current international $ 2000 31.234321514786664 2001 32.8280322733643 2002 35.89164807784833 2003 38.078344175411594 2004 40.238109040113386 2005 42.635530531302024 2006 46.2947420345454 2007 50.15878421421543 2008 53.52669365995292 2009 55.998747843892964 2010 56.739137547053176 2011 57.93424553753442 2012 60.50546894808669 2013 67.01073687138151 2014 70.76608954649106 2015 74.90180435677713 2016 78.57404364415459 2017 76.6088701879277 2018 77.20843943827941 2019 82.0553658226314 2020 81.85672821628498 2021 85.47309954469775