Year Number of 1990 389.11 1991 396.78 1992 404.65 1993 412.86 1994 421.33 1995 430.43 1996 427.83 1997 425.82 1998 424.43 1999 423.31 2000 422.65 2001 445.88 2002 471.11 2003 498.51 2004 527.84 2005 559.54 2006 575.28 2007 591.92 2008 610.8 2009 631.16 2010 653.35 2011 664.26 2012 676.46 2013 688.86 2014 702.25 2015 716.61 2016 732.06