Year Number of 1990 4549.49 1991 4719.39 1992 4896.37 1993 5086.92 1994 5297.56 1995 5561.18 1996 5757.42 1997 5956.99 1998 6147.24 1999 6347.22 2000 6545.87 2001 6809.29 2002 7053.78 2003 7301.64 2004 7548.95 2005 7804.13 2006 7969.6 2007 8122.74 2008 8268.59 2009 8426.64 2010 8572.98 2011 8777.88 2012 8976.12 2013 9163.96 2014 9325.39 2015 9485.02 2016 9667.91