Year current US$ 1995 4012851335.58489 1996 4254384095.79367 1997 4423757691.1268 1998 4494914645.37918 1999 4527987595.94719 2000 5148355971.75315 2001 4807604359.84034 2002 5005039852.62511 2003 6604568007.36874 2004 8719232422.47467 2005 10325776051.5812 2006 12100691065.3976 2007 14800646484.4949 2008 16321000000 2009 14969000000 2010 18937000000 2011 22975000000 2012 23886000000 2013 25794000000 2014 28722000000 2015 29922300000 2016 32053300000 2017 37902000000