Year % 1995 27.12 1999 27.09 2000 27.09 2001 27.09 2003 33.06 2004 32.7 2005 32.66 2006 32.62 2007 32.37 2008 31.9 2009 31.82 2010 31.81 2011 31.87 2013 30.15 2014 29.97 2015 25 2021 25.28