Year US Dollars adjusted for inflation) 1991 2800.401 1992 3102.237 1993 3227.386 1994 3281.075 1995 3319.175 1996 3343.052 1997 3235.216 1998 3344.999 1999 3124.555 2000 3153.568 2001 3277.131 2002 3411.29 2003 3234.623 2004 3427.981 2005 3596.664 2006 3655.538 2007 3790.656 2008 3899.258 2009 4031.054 2010 4103.246 2011 4201.734 2012 3386.982 2013 2679.134 2014 2803.225 2015 2775.615 2016 2704.6 2017 2587.207 2018 2575.864 2019 2538.369 2020 2576.119 2021 2536.177 2022 2482.287