Year Number 1993 13.59144 1994 15.42276 1995 15.31293 1998 12.69146 1999 12.54847 2000 12.23353 2001 12.72177 2002 12.65986 2003 12.92198 2004 12.90834 2005 13.11521 2006 12.82908 2007 12.81319 2008 12.58767 2009 12.37334 2010 12.03266 2011 11.67085 2012 11.34508 2013 11.23021 2014 11.113 2015 11.15229 2016 11.0616 2017 11.06981