Year US Dollars adjusted for inflation) 1991 9522.442 1992 8633.229 1993 8737.991 1994 9074.229 1995 9742.803 1996 10329.801 1997 9707.527 1998 9702.515 1999 9776.997 2000 10205.51 2001 10985.714 2002 12888.93 2003 13821.537 2004 15206.365 2005 16263.729 2006 17374.406 2007 18641.598 2008 20422.043 2009 19469.875 2010 19082.244 2011 19765.74 2012 19745.387 2013 20652.436 2014 21193.516 2015 22269.271 2016 23524.504 2017 25079.375 2018 26313.57 2019 27223.277 2020 27835.143 2021 28463.25 2022 29087.811