Year Number of 1990 224 1991 219.74 1992 206.83 1993 190.95 1994 171.48 1995 162.65 1996 159.91 1997 163.53 1998 162.73 1999 163.51 2000 169.95 2001 172.94 2002 180 2003 192.19 2004 204.24 2005 201.33 2006 185.31 2007 173.73 2008 180.68 2009 184.21 2010 185.55 2011 183.41 2012 181.83 2013 179.24 2014 177.48 2015 175.41 2016 173.85