Year current US$ 2005 5519381028.672151 2006 6253765483.335635 2007 8136344248.14639 2008 10806481172.902267 2009 9539588375.515978 2010 11664932798.612238 2011 15181469321.300438 2012 17581661255.17127 2013 22515843056.247856 2014 22190029768.203262 2015 17270403337.528267 2016 16404500416.712843 2017 19656706059.00263 2018 23331723783.236244 2019 22923106831.141846