Year Percent 1996 2.52784 1997 7.48527 1998 2.81967 1999 -11.828 2000 8.10408 2001 5.1734 2002 7.21454 2003 4.63778 2004 9.30125 2005 5.85798 2006 5.31765 2007 6.31897 2008 5.81619 2009 -2.72669 2010 0.98965 2011 2.20517 2012 -0.53373 2013 3.07206 2014 -1.36933 2015 1.25747 2016 3.33708 2017 2.39044