Year current US$ 2000 36.4628475 2001 39.27511311 2002 36.68064094 2003 46.18004562 2004 50.07811554 2005 59.93329728 2006 59.95412553 2007 57.67958222 2008 71.2849974 2009 56.72700304 2010 63.20158011 2011 87.4904298 2012 77.76193732 2013 80.76291669 2014 97.72372294 2015 92.80496522 2016 105.12086377 2017 104.80573238 2018 111.14366847 2019 119.33758311 2020 98.3255565 2021 67.97429529