Year Number of 1990 3640.11 1991 3849.72 1992 4081.19 1993 4336.61 1994 4621.42 1995 4944.3 1996 5182.09 1997 5444.52 1998 5727.81 1999 6032.22 2000 6362.62 2001 6741.67 2002 7159.91 2003 7616.36 2004 8109.83 2005 8651.06 2006 8909.51 2007 9170.82 2008 9383.33 2009 9703.98 2010 10038.02 2011 10516.47 2012 11040.83 2013 11591.1 2014 12156.93 2015 12736.44 2016 13340.02