Year current US$ 2000 37.34068519002168 2001 37.435568543039196 2002 36.45423491549512 2003 40.023465351978075 2004 45.234274912808864 2005 52.61321494631089 2006 58.60332207817867 2007 68.15395858096032 2008 77.5046453140867 2009 78.2230077186644 2010 90.29841106087885 2011 103.13745378504032 2012 108.10830713102717 2013 113.99093252563287 2014 115.34270744275537 2015 110.46675532686804 2016 111.88451869367222 2017 121.87988603874523 2018 128.76813414604158 2019 132.40999950249204 2020 131.8447469354794 2021 150.52745623440626