Year Number of 1990 771.84 1991 762.55 1992 761.56 1993 767.17 1994 755.25 1995 750.24 1996 735.9 1997 726.09 1998 714.97 1999 712.72 2000 688.09 2001 692.5 2002 686.55 2003 674.75 2004 672.26 2005 664.6 2006 660.14 2007 667.48 2008 666.63 2009 664.03 2010 656.41 2011 655.54 2012 644.67 2013 636.01 2014 619.24 2015 617.25 2016 616.33