Year Number of 1990 354.52 1991 367.85 1992 382.26 1993 396.96 1994 412.68 1995 429.56 1996 448.83 1997 469.5 1998 491.3 1999 514.52 2000 539.33 2001 558.04 2002 578.57 2003 600.54 2004 622.87 2005 645.23 2006 668.09 2007 690.8 2008 715.06 2009 740.73 2010 768.42 2011 787.1 2012 807.61 2013 829.24 2014 851.14 2015 872.82 2016 897.82