Year constant 2015 US$ 1993 2857.2169521202313 1994 2816.488377047061 1995 2737.6295588304656 1996 2936.976427550776 1997 2987.8492668564745 1998 2964.6756090682647 1999 3165.4883942791303 2000 3168.7328232103196 2001 3525.2379666931533 2002 4133.176196417661 2003 4343.472977173796 2004 4431.384905346354 2005 4808.4762283214795 2006 4984.071342438441 2007 5648.02116022188 2008 5374.570647567173 2009 5466.098507095328 2010 5927.002480411715 2011 6000.57251512864 2012 5264.572931554823 2013 5041.432400930644 2014 4870.349574208848 2015 3972.055859649371 2016 4679.579451619244 2017 4589.924399927299 2018 4012.259798520914 2019 3702.670526585857 2020 3881.9900725570715 2021 4142.011441653347