Year Number of 1990 537.71 1991 536.02 1992 536.63 1993 543.65 1994 558.67 1995 590.77 1996 576.18 1997 566.59 1998 554.31 1999 546.39 2000 546.19 2001 570.14 2002 592.03 2003 601.63 2004 606.98 2005 615.42 2006 621.07 2007 627.1 2008 628.75 2009 631.9 2010 638.29 2011 653.47 2012 672.69 2013 697.32 2014 725.38 2015 758 2016 793.26