Year Number of 1990 2467.69 1991 2600.92 1992 2811.71 1993 3006.84 1994 3205.25 1995 3385.65 1996 3554.92 1997 3787.72 1998 4011.02 1999 4328.86 2000 4565.16 2001 4826.56 2002 5104.7 2003 5366.01 2004 5562.7 2005 5792.36 2006 6093.54 2007 6369.04 2008 6670.43 2009 6973.67 2010 7297.63 2011 7518.66 2012 7730.86 2013 7805.9 2014 7921.16 2015 8028.12 2016 8111.67