Year Number of 1990 503.58 1991 514.7 1992 528.04 1993 542.07 1994 558.64 1995 567.38 1996 578.21 1997 587.61 1998 597.79 1999 606.39 2000 613.15 2001 627.86 2002 649.12 2003 680.27 2004 713.68 2005 749.89 2006 778.65 2007 802.61 2008 832.18 2009 862.66 2010 896.37 2011 930.75 2012 966.32 2013 1006.44 2014 1041.16 2015 1080.54 2016 1121.05