Year Number of 1990 358.37 1991 369.37 1992 381.71 1993 394.92 1994 408.5 1995 422.54 1996 433.21 1997 444.25 1998 455.77 1999 467.72 2000 480.61 2001 489.46 2002 499.1 2003 509.45 2004 521.16 2005 535.03 2006 551.91 2007 570.21 2008 591.11 2009 612.46 2010 634.44 2011 655.43 2012 677.42 2013 700.42 2014 724.74 2015 750.62 2016 777.02