Year US Dollars adjusted for inflation) 1995 3153.38339 1996 3233.09602 1997 3475.10205 1998 3573.08857 1999 3150.46359 2000 3405.7796 2001 3581.97423 2002 3840.3971 2003 4018.50634 2004 4392.27753 2005 4649.57627 2006 4896.82444 2007 5206.25315 2008 5509.05879 2009 5358.84374 2010 5411.8774 2011 5531.21835 2012 5501.69655 2013 5670.71173 2014 5593.0612 2015 5663.39238 2016 5852.3843 2017 5992.28207