Year Percent 1991 83.54951 1992 1065.32923 1993 747.56698 1994 1385.20203 1995 545.69531 1996 26.42101 1997 9.24021 1998 -0.96393 1999 2.16101 2000 12.49337 2001 2.51501 2002 3.11932 2003 6.00861 2004 8.31518 2005 16.13942 2006 11.30122 2007 20.9819 2008 27.76195 2009 -18.92973 2010 13.75655 2011 22.56609 2012 2.84794 2013 0.45752 2014 -0.55866 2015 -8.85512 2016 14.6714 2017 15.95334