Year Number of 1990 484.39 1991 482.44 1992 485.43 1993 486.31 1994 491.31 1995 498.05 1996 517.91 1997 536.64 1998 561.33 1999 575.38 2000 600.54 2001 619.68 2002 630.97 2003 647.54 2004 665.42 2005 684.74 2006 710.54 2007 741.23 2008 771.37 2009 794.05 2010 833.95 2011 863.92 2012 897.28 2013 922.97 2014 935.97 2015 939.42 2016 938.81