Year % 1988 33.01 1989 33.35 1990 33.53 1992 33.04 1995 92.88 1996 26.19 1997 26.22 1998 26.22 1999 27.43 2000 28.51 2001 28.8 2002 37.61 2003 32.8 2005 12.83 2006 12.79 2008 12.06 2009 11.95 2010 12.78 2011 12.66 2013 13.15 2014 13.28 2015 12.57 2016 12.57 2020 15.82 2021 15.34