Year Number of 1990 413.22 1991 415.16 1992 421.27 1993 426.18 1994 430.68 1995 433.8 1996 451.19 1997 465.48 1998 486.19 1999 502.21 2000 522.01 2001 535.61 2002 545.47 2003 564.27 2004 578.62 2005 592.44 2006 612.71 2007 634.44 2008 658.67 2009 681.34 2010 712.79 2011 728.12 2012 743.6 2013 747.67 2014 745.41 2015 744.47 2016 737.29