Year Percent 1996 6.88928 1997 13.08145 1998 5.12218 1999 -1.14798 2000 10.03454 2001 7.00815 2002 6.75045 2003 8.09245 2004 6.9321 2005 10.0014 2006 10.92403 2007 8.24085 2008 -5.16551 2009 -14.55986 2010 2.49255 2011 7.92444 2012 4.68129 2013 2.29997 2014 3.1609 2015 1.60766 2016 2.03355 2017 4.87885