Year Number of 1990 420.43 1991 431.7 1992 445.15 1993 476.94 1994 513.28 1995 537.8 1996 547.76 1997 553.8 1998 603.48 1999 612.01 2000 624.33 2001 645.74 2002 666.54 2003 706.14 2004 741.03 2005 767.8 2006 796.28 2007 813.91 2008 834.78 2009 851.75 2010 866.52 2011 884.85 2012 909.26 2013 938.56 2014 968.09 2015 1001.88 2016 1031.92