Year Number of 1990 214.64 1991 226.92 1992 219.8 1993 241.19 1994 244.81 1995 230.48 1996 211.76 1997 201.56 1998 200.74 1999 185.63 2000 189.65 2001 190.92 2002 180.32 2003 180.34 2004 173.67 2005 178.11 2006 176.86 2007 174.49 2008 170.3 2009 161.01 2010 150.29 2011 154 2012 151.01 2013 149 2014 145.05 2015 141.05 2016 139.08