Year US Dollars adjusted for inflation) 1991 13641.658 1992 14046.49 1993 14718.705 1994 15739.32 1995 16809.906 1996 17679.104 1997 18667.01 1998 19264.98 1999 20773.9 2000 22335.207 2001 22855.916 2002 24047.211 2003 24868.904 2004 26115.479 2005 26204.316 2006 26872.795 2007 27401.537 2008 27434.461 2009 28121.307 2010 29195.963 2011 30559.953 2012 30997.791 2013 31434.219 2014 31766.414 2015 32570.08 2016 32865.52 2017 34112.934 2018 35499.688 2019 37031.781 2020 38376.645 2021 39924.07 2022 41677.559