Year US Dollars adjusted for inflation) 1991 6855.389 1992 6803.423 1993 6624.199 1994 7042.488 1995 6900.236 1996 6897.966 1997 7098.231 1998 7259.126 1999 7115.505 2000 7383.634 2001 6884.562 2002 6290.719 2003 6358.606 2004 6404.481 2005 6549.979 2006 6888.775 2007 7030.786 2008 7290.007 2009 7316.562 2010 7210.502 2011 7106.817 2012 7020.959 2013 6943.421 2014 6902.86 2015 6652.395 2016 6735.076 2017 6874.272 2018 7012.747 2019 7106.458 2020 7206.298 2021 7305.886 2022 7426.604