Year % 1989 93.24856 1990 85.12403 1991 78.85492 1992 73.27446 1993 60.93397 1994 49.57553 1995 44.56746 1996 48.20919 1997 48.25394 1998 61.75445 1999 25.23176 2000 59.92148 2001 47.12253 2002 46.32043 2003 45.3313 2004 38.83799 2005 28.75435 2006 26.46226 2007 27.41669 2008 27.31863 2009 27.33989 2010 27.69222 2011 28.54526 2012 29.03679 2013 31.7196 2014 28.93011 2015 28.53347 2016 28.3372 2017 29.18521 2018 29.01665 2019 28.79889 2020 28.91861 2021 28.18243