Year US Dollars adjusted for inflation) 1991 2753.732 1992 2711.707 1993 2670.534 1994 2656.622 1995 2699.867 1996 2759.312 1997 2811.41 1998 2846.616 1999 2857.719 2000 2904.388 2001 2949.48 2002 2974.225 2003 3060.835 2004 3185.639 2005 3311.303 2006 3466.094 2007 3650.186 2008 3787.095 2009 3802.818 2010 3931.525 2011 4062.677 2012 4181.423 2013 4289.934 2014 4406.927 2015 4471.514 2016 4547.283 2017 4645.318 2018 4766.169 2019 4892.473 2020 5039.494 2021 5190.942 2022 5346.656