Year Number of 1990 466.05 1991 481.52 1992 500.07 1993 528.48 1994 560.08 1995 588.79 1996 613.9 1997 637.36 1998 668.95 1999 704.99 2000 742.67 2001 777.86 2002 813.43 2003 846.1 2004 877.74 2005 902.43 2006 918.66 2007 935.67 2008 957.48 2009 986.05 2010 1022.88 2011 1045.89 2012 1070.58 2013 1096.04 2014 1124.8 2015 1156.76 2016 1183.91