Year Number of 1990 36842.44 1991 37952.37 1992 39356.48 1993 40791.98 1994 42236.39 1995 43638.27 1996 44869.88 1997 46074.1 1998 47395.27 1999 49276.01 2000 51453.93 2001 53921.14 2002 55898.93 2003 56483.82 2004 56952.22 2005 57960.76 2006 58826.05 2007 59875.28 2008 60878.25 2009 61793.72 2010 62669.27 2011 63585.3 2012 64720.46 2013 65708.55 2014 67373.58 2015 67934.09 2016 67849.72