Year US Dollars adjusted for inflation) 1991 4179.629 1992 4078.968 1993 4025.561 1994 2688.08 1995 2673.066 1996 2572.186 1997 2638.978 1998 2456.877 1999 2375.432 2000 2353.425 2001 2460.387 2002 2626.777 2003 2812.613 2004 3002.81 2005 3257.544 2006 3503.097 2007 3619.005 2008 3976.225 2009 3962.006 2010 4384.468 2011 4602.995 2012 4683.134 2013 5002.004 2014 5192.362 2015 4835.749 2016 5221.866 2017 5496.895 2018 5797.729 2019 6096.224 2020 6406.537 2021 6752.355 2022 7119.855