Year US Dollars adjusted for inflation) 1991 66901.125 1992 68492.805 1993 70807.523 1994 73151.945 1995 73252.859 1996 73547.703 1997 73538.156 1998 73606.5 1999 72497.539 2000 72401.453 2001 72321.664 2002 71737.586 2003 71405.594 2004 71171.492 2005 69698.492 2006 70024.172 2007 70878.664 2008 72277.805 2009 74331.867 2010 75422.688 2011 76078.531 2012 77355.352 2013 78135.977 2014 78324.391 2015 78811.43 2016 79192.734 2017 79647.602 2018 79861.125 2019 81233.945 2020 82907.734 2021 84570.969 2022 86204.141