Year Number of 1990 4980.74 1991 5354.57 1992 5770.24 1993 6235.83 1994 6800.81 1995 7448.88 1996 7937.11 1997 8434.33 1998 8982.27 1999 9527.89 2000 10006.75 2001 10397.2 2002 10692.05 2003 10940.89 2004 11236.24 2005 11563.67 2006 11719.47 2007 11895.67 2008 12154.78 2009 12460.81 2010 12792.79 2011 13068.96 2012 13406.82 2013 13716.4 2014 14237.56 2015 14795.97 2016 15464.51