Year US Dollars adjusted for inflation) 1991 8186.538 1992 6078.586 1993 4549.953 1994 3590.036 1995 3104.569 1996 3209.449 1997 3371.893 1998 3658.006 1999 3886.953 2000 4209.479 2001 4473.958 2002 4785.268 2003 5152.572 2004 5464.006 2005 6681.144 2006 8715.066 2007 10625.499 2008 11445.515 2009 12221.474 2010 12565.604 2011 12364.365 2012 12375.796 2013 12857.178 2014 12864.98 2015 12786.03 2016 12162.483 2017 12018.685 2018 12174.36 2019 12454.415 2020 12772.159 2021 13173.83 2022 13622.572