Year US Dollars adjusted for inflation) 1991 1524.02 1992 1597.995 1993 1306.647 1994 1398.528 1995 1370.647 1996 1360.069 1997 1393.305 1998 1442.362 1999 1382.165 2000 1321.971 2001 1428.796 2002 1493.742 2003 1652.882 2004 2130.991 2005 2408.07 2006 2339.471 2007 2337.308 2008 2328.746 2009 2345.889 2010 2577.394 2011 2486.387 2012 2619.174 2013 2670.768 2014 2756.966 2015 2706.937 2016 2431.138 2017 2361.733 2018 2392.835 2019 2456.47 2020 2506.214 2021 2530.629 2022 2556.838