Year Number of 1990 5087.67 1991 5289.02 1992 5545.42 1993 5775.99 1994 5941.63 1995 5974.61 1996 6164.61 1997 6198.01 1998 6219.33 1999 6296.03 2000 6343.01 2001 6243.76 2002 6239.39 2003 6344.36 2004 6469.73 2005 6573.39 2006 6691.58 2007 6689.45 2008 6700.53 2009 6832.11 2010 6767.86 2011 6753.9 2012 6750.96 2013 6712.74 2014 6753.16 2015 6809.08 2016 6874.45