Year US Dollars adjusted for inflation) 1991 69616.125 1992 72145.125 1993 71438.812 1994 71957.062 1995 74088.109 1996 73588.008 1997 73705.406 1998 77508.719 1999 77124.508 2000 78400.688 2001 86387.438 2002 87754.461 2003 88459.875 2004 88756.781 2005 89459.531 2006 87730.641 2007 85893.891 2008 86503.305 2009 89009.789 2010 89159.469 2011 88065.297 2012 85105.219 2013 85377.562 2014 85378.289 2015 83991.547 2016 81700.273 2017 78273.172 2018 74652.336 2019 76708.039 2020 78587.094 2021 79734.562 2022 80516.891