Year Number of 1990 447.59 1991 447.84 1992 466.86 1993 477.67 1994 491.33 1995 517.11 1996 525.52 1997 541.73 1998 560.83 1999 586.59 2000 620.55 2001 647.75 2002 671.25 2003 686.7 2004 698.27 2005 715.08 2006 722.69 2007 730.5 2008 747.36 2009 761.73 2010 782.68 2011 791.84 2012 808.89 2013 821.56 2014 828.18 2015 843.87 2016 869.8