Year % 1993 4.88 1996 4.79 2001 14.98 2002 15.41 2003 15.32 2004 15.85 2005 15.76 2006 15.37 2007 15.28 2008 15.28 2009 15.1 2010 15.15 2011 15.08 2012 14.69 2013 14.69 2014 14.57 2015 15.58 2016 15.43 2017 17.59 2018 16.95 2019 15.6 2020 15.54 2021 15.54