Year Number of 1990 407.12 1991 411.11 1992 433.09 1993 458.3 1994 472 1995 485.1 1996 515.51 1997 537.58 1998 550.29 1999 549.37 2000 543.4 2001 540.21 2002 539.22 2003 546.93 2004 556.02 2005 565.83 2006 575.09 2007 592.29 2008 606.65 2009 620.54 2010 644.68 2011 661.59 2012 681.67 2013 698.71 2014 719.9 2015 742.16 2016 764.23