Year US Dollars adjusted for inflation) 1995 41473.32844 1996 41185.03992 1997 40147.42062 1998 38874.50983 1999 35824.1351 2000 35792.70979 2001 35051.80226 2002 35522.72737 2003 41189.46318 2004 44820.20002 2005 47847.82359 2006 49268.26312 2007 49588.76428 2008 47965.00883 2009 41936.81677 2010 38497.61696 2011 39652.17118 2012 39733.28919 2013 37924.47244 2014 36259.66868 2015 35053.59084 2016 35250.91458 2017 33545.61763