Year current US$ 2000 19.78130531 2001 22.66413116 2002 24.67282104 2003 25.30601883 2004 29.03012466 2005 32.52131653 2006 33.02656555 2007 30.92131042 2008 49.00638199 2009 55.72327423 2010 54.09758377 2011 66.05435944 2012 69.01600647 2013 72.11994934 2014 73.5883255 2015 72.51950836 2016 78.35865784 2017 79.16844177 2018 93.01556396 2019 114.48534393 2020 112.21422577 2021 122.41645813