Year Number of 1990 1672.46 1991 1791.36 1992 1920.89 1993 2012.86 1994 2108.72 1995 2207.22 1996 2294.24 1997 2390.69 1998 2443.48 1999 2637.23 2000 2823.77 2001 2978.2 2002 3116.75 2003 3265.16 2004 3464.28 2005 3705.69 2006 3741.1 2007 3792.35 2008 3810.85 2009 3821 2010 3837.63 2011 3887.35 2012 3991.04 2013 4136.62 2014 4260.52 2015 4451.89 2016 4647.15