Year U.S. dollars (Billions) 2002 4.367 2003 4.553 2004 5.146 2005 6.167 2006 6.925 2007 8.556 2008 10.297 2009 12.066 2010 15.325 2011 17.890 2012 20.293 2013 20.170 2014 20.616 2015 20.057 2016 18.020 2017 18.883 2018 18.336 2019 18.876 2020 20.136 2021 14.288 2022 14.467