Year Number of 1990 1742.49 1991 1895.77 1992 2069.06 1993 2257.57 1994 2469.83 1995 2709.57 1996 2971.34 1997 3266.17 1998 3599.07 1999 3970.61 2000 4381.26 2001 4709.3 2002 5058.78 2003 5432.42 2004 5838.19 2005 6277.67 2006 6589.07 2007 6909.51 2008 7235.17 2009 7579.49 2010 7938.37 2011 8230.8 2012 8524.34 2013 8816.66 2014 9115.74 2015 9438.02 2016 9775.59