Year US Dollars adjusted for inflation) 1991 67516.578 1992 74213.57 1993 72228.125 1994 72125.586 1995 72770.094 1996 74140.18 1997 94364.297 1998 102740.148 1999 104723.172 2000 110427.07 2001 108894.359 2002 109234.758 2003 103746.617 2004 108551.93 2005 99414.422 2006 102403.133 2007 97693.266 2008 94651.141 2009 89821.039 2010 93758.352 2011 97862.75 2012 94978.906 2013 92650.375 2014 90808.078 2015 89306.438 2016 88623.305 2017 88120.789 2018 88771.258 2019 89475.102 2020 90382.891 2021 92652.211 2022 94904.812