Year Number of 1990 521.09 1991 525.55 1992 528.71 1993 568.58 1994 587.13 1995 604.96 1996 621.5 1997 634.98 1998 646.15 1999 657.56 2000 668.76 2001 676.44 2002 682.79 2003 690.44 2004 696.68 2005 702.46 2006 708.04 2007 713.55 2008 718.53 2009 729.49 2010 738.38 2011 747.49 2012 755.41 2013 772.63 2014 788.52 2015 804.74 2016 823.78