Year US Dollars adjusted for inflation) 1991 4650.658 1992 4933.632 1993 5275.968 1994 5733.601 1995 6103.164 1996 6553.489 1997 7025.965 1998 7113.317 1999 7283.101 2000 7354.349 2001 7497.963 2002 7677.547 2003 7663.325 2004 7869.107 2005 7795.331 2006 7939.79 2007 8354.731 2008 8542.135 2009 8701.514 2010 8965.237 2011 9276.975 2012 9578.275 2013 9892.908 2014 10133.384 2015 10299.927 2016 10474.325 2017 10797.975 2018 11093.188 2019 11410.599 2020 12188.698 2021 13058.133 2022 13992.396