Year Percent 1989 0.04064 1993 0.00241 1994 -0.00121 1995 0.00794 2005 0.18851 2006 1.66187 2007 0.18552 2008 0.43282 2009 0.31628 2010 2.34252 2011 0.63657 2012 0.0609 2013 3.26052 2014 0.57195 2015 0.01028 2016 0.31522 2017 0.21067