Year current US$ 2003 6.89100123 2004 7.79160423 2005 10.12390728 2006 10.93988977 2007 5.14821722 2008 21.11171712 2009 22.14456238 2010 26.64465476 2011 33.40672935 2012 42.30392673 2013 53.42837834 2014 50.40385541 2015 58.25115503 2016 46.15527838 2017 57.24564865 2018 48.74410377 2019 45.71874847 2020 66.81482286 2021 85.64718663