Year Number of 1990 427.16 1991 435.52 1992 448.25 1993 464.13 1994 481.32 1995 499.07 1996 505.88 1997 512.43 1998 519.14 1999 526.38 2000 534.65 2001 533.07 2002 532.59 2003 533.08 2004 534.09 2005 535.61 2006 548.12 2007 561.08 2008 575.06 2009 589.67 2010 605.07 2011 633.1 2012 663.26 2013 695.37 2014 729.59 2015 765.97 2016 803.8