Year Number of 1990 4313.94 1991 4459.33 1992 4616.16 1993 4783.13 1994 4962.56 1995 5160 1996 5393.52 1997 5655.96 1998 5943.47 1999 6249.03 2000 6574.61 2001 6841.13 2002 7110.45 2003 7389.37 2004 7692.71 2005 8034.76 2006 8330.48 2007 8652.07 2008 9013.11 2009 9399.42 2010 9818.65 2011 10177.71 2012 10570.93 2013 10986.46 2014 11427.87 2015 11895.62 2016 12377.86