Year Number of 1990 3635.74 1991 3786.88 1992 3945.01 1993 4107.77 1994 4275.75 1995 4455.4 1996 4590.51 1997 4736.82 1998 4889.09 1999 5046.65 2000 5207.62 2001 5362.33 2002 5535.14 2003 5719.07 2004 5914.79 2005 6128.1 2006 6238.34 2007 6354.61 2008 6478.82 2009 6600.6 2010 6727.99 2011 6842.68 2012 6971.36 2013 7101.6 2014 7238.53 2015 7382.75 2016 7535.2