Year current US$ 2000 23.097672797882893 2001 23.35717880063525 2002 23.238097241729065 2003 30.254723275250043 2004 35.25744450078806 2005 41.077555506501085 2006 48.71479140386211 2007 57.69527737070818 2008 66.88571407945678 2009 61.633639629930244 2010 67.12695454905294 2011 72.621634092334 2012 75.65487691750326 2013 81.29210762397291 2014 80.31990265424979 2015 72.16346682675102 2016 70.27688347703301 2017 68.7589981711175 2018 73.33408602465249 2019 73.44830720152702 2020 75.18372788100254 2021 82.12692052190438