Year % 1996 25.08 1999 22.19 2000 15.39 2001 12.49 2002 12.49 2003 13.92 2004 13.91 2005 13.91 2006 12.35 2007 14.26 2008 13.64 2009 14.08 2010 14.83 2011 14.83 2012 15.09 2013 15.16 2014 14.88 2015 14.9 2016 14.26 2017 13.51 2018 16.21 2019 13.73 2020 13.73 2021 13.73