Year Number of 1990 4498.02 1991 4615.46 1992 4737.64 1993 4868.74 1994 5006.88 1995 5157.5 1996 5302.37 1997 5455.77 1998 5623.23 1999 5807.67 2000 6004.19 2001 6097.65 2002 6197.07 2003 6302.91 2004 6424.09 2005 6557.15 2006 6662.41 2007 6781.22 2008 6906.73 2009 7036.8 2010 7155.21 2011 7354.19 2012 7573.27 2013 7798.83 2014 8033.96 2015 8263.57 2016 8496.89