Year % 2002 6.01 2003 4.73 2004 5.57 2005 5.11 2006 5 2007 5.14 2008 3.74 2009 3.59 2010 3.84 2011 3.35 2012 3.06 2013 3.64 2014 3.69 2015 3.51 2016 3.73 2017 4.46 2018 4.3 2019 4.22