Year US Dollars adjusted for inflation) 1991 1214.395 1992 1137.774 1993 941.356 1994 1056.569 1995 1108.247 1996 1165.963 1997 1289.027 1998 1213.772 1999 1200.573 2000 1150.202 2001 1097.416 2002 1055.71 2003 1076.971 2004 1068.133 2005 1049.621 2006 1062.496 2007 1063.141 2008 1064.093 2009 1078.952 2010 1100.007 2011 1132.732 2012 1154.586 2013 1167.152 2014 1201.8 2015 1231.732 2016 1257.832 2017 1294.703 2018 1337.743 2019 1381.81 2020 1426.83 2021 1471.517 2022 1517.772