Year Number of 1990 14127.41 1991 14827.55 1992 15633.02 1993 16359.36 1994 17075.56 1995 17977.42 1996 18690.81 1997 19376.83 1998 20073.07 1999 20702.04 2000 21190.91 2001 21654.3 2002 22094.75 2003 22582.64 2004 23144.88 2005 23724.55 2006 24132.48 2007 24658.09 2008 25154.92 2009 25418.55 2010 25937.1 2011 26411.62 2012 26640.41 2013 26719.38 2014 26469.1 2015 26687.84 2016 26952.88