Year Number 1993 11.48803 1994 11.48595 1995 11.53264 1996 11.59201 1997 11.9609 1998 13.36129 1999 12.06831 2000 11.7126 2001 11.8532 2002 11.98982 2003 12.08518 2004 11.71876 2005 11.52171 2006 11.48246 2007 11.3767 2008 11.40949 2009 11.44857 2010 11.55701 2011 11.60737 2012 11.48958 2013 12.25138 2014 12.36069 2015 12.27296 2016 12.01514 2017 11.94042 2018 11.92749