Year Percent 1997 0.85118 1998 0.36881 1999 0.92702 2000 -0.83843 2001 -2.67646 2002 -1.85659 2003 -1.22183 2004 -5.03181 2005 0.21996 2006 0.66212 2007 1.74903 2008 -0.69536 2009 1.5365 2010 -6.88464 2011 4.01098 2012 1.44363 2013 2.80954 2014 1.44203 2015 -0.0984 2016 0.17818 2017 -0.06033