Year US Dollars adjusted for inflation) 1991 4474.268 1992 4589.394 1993 4772.917 1994 5012.482 1995 5297.096 1996 5583.673 1997 5737.325 1998 4844.459 1999 4760.554 2000 4875.481 2001 4952.985 2002 5115.508 2003 5269.144 2004 5485.392 2005 5778.962 2006 5976.868 2007 6281.161 2008 6491.99 2009 6587.846 2010 6838.002 2011 7122.257 2012 7402.49 2013 7710.311 2014 7979.245 2015 8441.669 2016 8631.727 2017 8988.56 2018 9387.67 2019 9806.787 2020 10256.849 2021 10738.811 2022 11231.815