Year US Dollars adjusted for inflation) 1991 6646.642 1992 6779.238 1993 6862.693 1994 6945.711 1995 7079.224 1996 7095.001 1997 7187.285 1998 7315.179 1999 7369.176 2000 7387.131 2001 7321.638 2002 7516.571 2003 7500.537 2004 7477.738 2005 7221.205 2006 7133.336 2007 7504.7 2008 7640.305 2009 7575.692 2010 7719.547 2011 7939.852 2012 7266.427 2013 7955.427 2014 7933.048 2015 8046.836 2016 8000.259 2017 8050.516 2018 8156.508 2019 8272.943 2020 8391.338 2021 8511.1 2022 8634.748