Year US Dollars adjusted for inflation) 1991 1091.394 1992 1062.508 1993 1040.478 1994 1023.326 1995 1027.838 1996 1046.794 1997 1056.191 1998 1068.106 1999 1091.92 2000 1116.501 2001 1153.241 2002 1183.446 2003 1233.362 2004 1296.026 2005 1364.761 2006 1389.936 2007 1453.094 2008 1477.223 2009 1490.666 2010 1543.263 2011 1621.777 2012 1644.177 2013 1703.187 2014 1751.644 2015 1814.67 2016 1879.41 2017 1943.804 2018 2014.264 2019 2091.048 2020 2168.438 2021 2239.139 2022 2309.886