Year % 1994 24.05 1996 21.14 1997 21.23 1998 16.68 2000 12.36 2001 12.4 2003 12.41 2006 13.15 2008 12.69 2009 12.69 2010 14.53 2011 14.94 2012 14.88 2013 15.32 2014 15.64 2015 15.63 2016 14.84 2019 14.86 2020 14.88 2021 14.88