Year US Dollars adjusted for inflation) 1991 3183.045 1992 3427.333 1993 3612.552 1994 4167.151 1995 4611.646 1996 4984.995 1997 5389.202 1998 5904.109 1999 6395.894 2000 7109.67 2001 7046.164 2002 7195.593 2003 7288.002 2004 7805.898 2005 8130.899 2006 8553.056 2007 9601.664 2008 9976.9 2009 9580.49 2010 9486.783 2011 9646.528 2012 9509.268 2013 9354.389 2014 9189.411 2015 9074.83 2016 9223.113 2017 9399.923 2018 9625.819 2019 9878.078 2020 10141.841 2021 10402.459 2022 10675.191