Year current US$ 2000 3360.678060681196 2001 3713.5167609267605 2002 4381.989692251539 2003 5854.697322983768 2004 7216.364041490499 2005 8538.238628975956 2006 10243.972630128377 2007 13193.38031742295 2008 14305.919160052428 2009 11532.879939404278 2010 11282.422335869393 2011 13704.931508402044 2012 13778.337233375392 2013 15315.388435920795 2014 16276.91132775911 2015 14040.886020332035 2016 14872.602416664362 2017 16600.900748468935 2018 18854.373307904145 2019 19062.769488820693 2020 19133.100649843327 2021 22462.364753587786