Year % 1999 0.97 2001 0.46 2002 0.56 2004 0.47 2005 0.44 2006 0.39 2007 0.52 2009 0.53 2010 0.53 2011 0.79 2012 0.68 2013 0.63 2014 0.79 2015 0.72 2016 0.96 2017 0.83 2018 0.82