Year Number of 1990 557.53 1991 558.28 1992 560.32 1993 562.61 1994 584.07 1995 606.85 1996 610.82 1997 617.38 1998 636.16 1999 646.01 2000 647.59 2001 638.96 2002 642.64 2003 655.36 2004 663.15 2005 670.64 2006 691.61 2007 662.74 2008 664.71 2009 682.73 2010 692.07 2011 720.45 2012 739.69 2013 753.16 2014 764.84 2015 763.9 2016 774.89