Year % 1988 25.12 1989 27.2 1990 27.39 1992 27.57 1995 86.48 1996 22.58 1997 22.63 1998 22.63 1999 24.32 2000 24.21 2001 23.67 2002 23.68 2003 23.62 2005 10.26 2006 10.31 2008 10.67 2009 9.68 2010 10.81 2011 10.94 2013 11.09 2014 11.54 2015 11.09 2016 11.34 2020 12.33 2021 12.33