Year Number of 1990 495.04 1991 504.4 1992 522.27 1993 538.45 1994 554.19 1995 566.17 1996 581.35 1997 598.23 1998 599.58 1999 601.16 2000 607.88 2001 594.5 2002 604.83 2003 610.21 2004 624.69 2005 647.27 2006 657.44 2007 680.4 2008 695.75 2009 718.35 2010 745.64 2011 766.27 2012 787.29 2013 819.28 2014 870.56 2015 932.63 2016 978.89