Year % 1989 17.57 1990 16.56 1993 15.61 1995 12.41 1996 12.32 1997 17.76 1998 6.71 1999 11.3 2000 6.62 2001 6.59 2002 6.56 2003 6.53 2004 6.52 2005 6.51 2006 6.5 2007 6.66 2008 6.65 2009 6.62 2010 7.86 2011 7.96 2012 7.86 2013 7.25 2016 6.77 2017 6.87 2018 7.03 2019 9.07 2020 6.85 2021 6.85