Year Number of 1990 6960.49 1991 7166.43 1992 7365.05 1993 7562.53 1994 7761.58 1995 7969.46 1996 8216.33 1997 8480.59 1998 8757.53 1999 9034.9 2000 9330.45 2001 9585.57 2002 9859.68 2003 10147.37 2004 10441 2005 10751.47 2006 10897.42 2007 11047.82 2008 11203.35 2009 11361.84 2010 11528.66 2011 11893.92 2012 12245.17 2013 12596.07 2014 12946.67 2015 13297.02 2016 13649.23