Year Number of 1990 374.39 1991 383.47 1992 397.69 1993 409.42 1994 427.69 1995 433.38 1996 442.8 1997 451.05 1998 463.01 1999 477.98 2000 485.7 2001 500.33 2002 521.12 2003 549.49 2004 581.3 2005 617.83 2006 645.85 2007 669.48 2008 700.56 2009 734.31 2010 775.54 2011 816.12 2012 862.64 2013 913.42 2014 956.07 2015 1005.51 2016 1058.34