Year US Dollars adjusted for inflation) 1991 12253.382 1992 12315.77 1993 12379.694 1994 12369.45 1995 12650.785 1996 12831.041 1997 12978.005 1998 13050.7 1999 13197.888 2000 13218.304 2001 13226.645 2002 13744.433 2003 14223.041 2004 14649.791 2005 15422.183 2006 16123.549 2007 16532.52 2008 16107.162 2009 15814.07 2010 15824.168 2011 15573.38 2012 15723.428 2013 16197.341 2014 16250.248 2015 15868.779 2016 14962.346 2017 14959.31 2018 14701.548 2019 14474.323 2020 14353.315 2021 14330.636 2022 14407.979