Year US Dollars adjusted for inflation) 1991 20791.195 1992 21655.625 1993 22907.951 1994 24235.248 1995 25820.438 1996 27252.213 1997 28327.539 1998 28366.941 1999 30902.6 2000 32306.646 2001 33107.105 2002 34606.621 2003 35688.859 2004 36747.285 2005 37863.555 2006 39378.383 2007 41075.871 2008 42141.379 2009 42731.145 2010 45000.48 2011 45961.109 2012 46264.129 2013 46976.109 2014 47537.398 2015 48391.836 2016 49316.703 2017 50659.035 2018 51896.695 2019 53053.562 2020 54303.711 2021 55614.496 2022 56990.117