Year US Dollars adjusted for inflation) 1991 13512.544 1992 13738.964 1993 13640.222 1994 13689.637 1995 13332.349 1996 13555.862 1997 13906.956 1998 14643.037 1999 14443.835 2000 14699.871 2001 14571.642 2002 14379.872 2003 14485.979 2004 14904.525 2005 15186.132 2006 16135.946 2007 17094.992 2008 17570.916 2009 17432.855 2010 18196.494 2011 20090.086 2012 21016.299 2013 21549.273 2014 22635.719 2015 23238.492 2016 23714.049 2017 24680.26 2018 25685.396 2019 26726.797 2020 27812.584 2021 28957.867 2022 30156.904