Year US Dollars 1990 26430 1991 27560 1992 31220 1993 32650 1994 33950 1995 34660 1996 33810 1997 33520 1998 31450 1999 29900 2000 30870 2001 34410 2002 37090 2003 40560 2004 49750 2005 53620 2006 58810 2007 74960 2008 69530 2009 70380 2010 85790 2011 101000 2012 107980 2013 117970 2014 118020 2015 98320 2016 96570