Year Number of 1990 424.1 1991 434.88 1992 446.61 1993 459.53 1994 473.66 1995 489.01 1996 495.31 1997 502.03 1998 509.58 1999 517.64 2000 526.21 2001 534.93 2002 544.13 2003 555.75 2004 567.76 2005 580.3 2006 590.36 2007 600.7 2008 611.76 2009 624.79 2010 640.18 2011 662.58 2012 687.8 2013 713.26 2014 738.46 2015 763.06 2016 789.38