Year Number of 1990 378.89 1991 397.32 1992 419.11 1993 431.1 1994 452.58 1995 479.68 1996 500.55 1997 527.81 1998 541.2 1999 554.02 2000 576.21 2001 579.55 2002 575.19 2003 567.8 2004 562.93 2005 564.82 2006 566.4 2007 571.41 2008 604.52 2009 636.98 2010 668.95 2011 687.58 2012 708.43 2013 724.53 2014 740.97 2015 761.16 2016 779.32