Year % 1993 24.73 1997 31.62 1998 31.42 2000 16.87 2003 14.42 2005 15.4 2006 15.03 2007 15 2008 15.61 2009 15.61 2010 15.61 2011 15.47 2012 16.55 2013 16.51 2014 16.65 2015 16.67 2016 16.66 2018 16.73 2019 17.11 2020 17.92 2021 17.87