Year current US$ 2000 24.815857867983784 2001 24.41581983840779 2002 23.737704856466028 2003 26.933262400409912 2004 31.44204627210128 2005 37.47578762386742 2006 44.59713434577401 2007 54.74532769684991 2008 68.3147584989824 2009 75.06553246323055 2010 87.22784063884356 2011 103.1684924095552 2012 111.44089600159106 2013 121.23457303471648 2014 127.94009371093308 2015 128.3149202505836 2016 125.05428937693361 2017 134.53599899179534 2018 141.0133134461628 2019 144.4399797946541 2020 149.409257719915 2021 166.89027581407217