Year current international $ 2000 13.4391202438666 2001 16.8905435947343 2002 19.9405432972227 2003 20.0681465888706 2004 17.6551729173852 2005 16.7405282324631 2006 17.3274666644918 2007 15.8508736625566 2008 15.6332522200569 2009 12.760751590521 2010 11.7142067217933 2011 16.9432604549745 2012 19.345742937463 2013 15.3441507936393 2014 19.8713935601931 2015 12.5079298951831 2016 13.0239678300171 2017 5.21212357061091 2018 13.4269730043362 2019 15.9292572996274 2020 23.476629546543 2021 19.712640191624