Year US Dollars adjusted for inflation) 1991 3406.106 1992 3014.688 1993 2977.917 1994 3181.815 1995 3128.789 1996 3403.982 1997 3463.165 1998 3518.855 1999 3456.299 2000 3169.462 2001 3057.76 2002 2652.642 2003 2103.792 2004 1898.553 2005 1766.411 2006 1678.283 2007 1589.962 2008 1285.399 2009 1375.411 2010 1559.236 2011 1774.837 2012 1967.568 2013 2018.032 2014 2021.109 2015 1997.944 2016 1959.816 2017 1945.924 2018 1911.916 2019 1869.473 2020 1811.065 2021 1759.499 2022 1736.256