Year current US$ 1998 447.75176437950205 1999 427.79665363650497 2000 382.1721725339798 2001 456.27250166493985 2002 572.6336181918967 2003 673.1908687034636 2004 761.0827362003503 2005 947.1403906527012 2006 1378.4481650452883 2007 2062.9689315350474 2008 3092.188039325102 2009 3275.46160334341 2010 4040.2053095331717 2011 4784.739454342085 2012 5294.537687744208 2013 5674.20814037456 2014 6051.6970620124275 2015 4460.301609763837 2016 3029.305998617436 2017 3226.1524483414455 2018 3414.8229671103286 2019 3656.1416822944548 2020 3530.6605367863717 2021 3965.424395761959