Year US Dollars 1992 37808475385.4109 1993 37885633312.1158 1994 36693762581.0382 1995 37151138566.48161 1996 38369193864.1332 1997 40781380657.43669 1998 43219835492.5153 1999 45625349285.1057 2000 48139439612.74871 2001 51196762145.30321 2002 54227890708.0636 2003 57837796468.93461 2004 64481437277.2507 2005 71385556336.922 2006 78678148386.36079 2007 92967783989.76807 2008 104964004432.00301 2009 110908562689.71703 2010 122251186900.03697 2011 136295408676.256 2012 150886306570.36902 2013 167457416596.67996 2014 182092766315.733 2015 194128698214.97998 2016 211402269413.54898 2017 230950018368.45703