Year % 1988 31.03 1989 33.13 1990 33.15 1992 31.38 1995 98.31 1996 26.02 1997 26.03 1998 26.03 1999 26.9 2000 26.9 2001 27.1 2002 39.09 2003 37.89 2005 12.61 2006 12.58 2008 12.36 2009 12.33 2010 12.35 2011 12.34 2013 12.36 2014 12.47 2015 13.2 2016 13.2 2020 13.26 2021 13.26