Year Number of 1990 5673.19 1991 6037.15 1992 6435.9 1993 6862.08 1994 7310.11 1995 7797.19 1996 8229.09 1997 8713.74 1998 9250.27 1999 9816.11 2000 10431.18 2001 11033.11 2002 11696.99 2003 12418.99 2004 13206.7 2005 14074.71 2006 15083.23 2007 16192.97 2008 17409.9 2009 18747.12 2010 20212.55 2011 20835.29 2012 21473.71 2013 22115.46 2014 22691.61 2015 23335 2016 24004.41