Year US Dollars adjusted for inflation) 1991 56711.555 1992 54486.207 1993 55762.77 1994 57175.07 1995 54863.141 1996 56819.59 1997 59622.883 1998 61126.496 1999 61190.277 2000 62204.953 2001 63930.48 2002 65075.555 2003 66842.523 2004 71723.656 2005 74759.305 2006 76364.047 2007 81113.25 2008 81800.391 2009 79533.68 2010 75451.117 2011 76326.984 2012 75772.516 2013 77335.008 2014 76776.328 2015 77888.023 2016 81171.391 2017 83745.289 2018 86609.43 2019 89582.312 2020 92530.219 2021 94804.383 2022 96978.734