Year Number of 1990 2937.24 1991 3056.82 1992 3181.56 1993 3293.79 1994 3450.75 1995 3584.15 1996 3750.99 1997 3883.32 1998 4053.94 1999 4191.98 2000 4272.91 2001 4310.93 2002 4348.17 2003 4333.64 2004 4251.07 2005 4198.1 2006 4175.32 2007 4106.7 2008 4120.54 2009 4159.11 2010 4172.22 2011 4041.98 2012 4048.59 2013 4029.02 2014 4067.67 2015 4104.37 2016 4133.88