Year Number of 1990 403.16 1991 408.52 1992 419.44 1993 427.33 1994 443.62 1995 464.83 1996 482.66 1997 492 1998 505.56 1999 521.67 2000 541.86 2001 558.64 2002 575.43 2003 592.22 2004 613.99 2005 633.04 2006 652.98 2007 673.02 2008 697.15 2009 726.52 2010 752.05 2011 774.33 2012 796.92 2013 818.4 2014 836.97 2015 856.74 2016 875.9