Year US Dollars adjusted for inflation) 1991 1463.324 1992 1504.703 1993 1538.862 1994 1597.714 1995 1685.231 1996 1779.941 1997 1822.563 1998 1896.84 1999 2023.4 2000 2068.889 2001 2109.39 2002 2132.823 2003 2232.507 2004 2345.614 2005 2493.374 2006 2714.065 2007 2968.495 2008 3084.528 2009 3323.965 2010 3649.342 2011 3867.183 2012 4054.074 2013 4231.421 2014 4465.007 2015 4732.915 2016 4982.217 2017 5253.95 2018 5590.82 2019 5933.622 2020 6288.645 2021 6654.803 2022 7033.14