Year Number of 1990 354.71 1991 363.51 1992 374.19 1993 388.07 1994 404.72 1995 421.1 1996 435.76 1997 451.21 1998 466.01 1999 471.55 2000 483.03 2001 475.24 2002 475.1 2003 479.11 2004 490.71 2005 507.77 2006 533.11 2007 556.57 2008 581.46 2009 610.82 2010 643.7 2011 677.84 2012 713.32 2013 752.38 2014 797.21 2015 840.28 2016 892.72