Year Percent 1996 4.23 1997 5.16 1998 4.29 2006 4.96 2007 5.87 2009 4.8 2010 2.21 2011 1.62 2012 1.6 2013 1.2 2014 1.46 2015 1.47 2016 2.01 2017 1.67 2018 0.87 2019 1.58