Year Number of 1990 407.07 1991 431.15 1992 453.87 1993 457.99 1994 493.57 1995 511.36 1996 537.88 1997 552.44 1998 566.2 1999 582.32 2000 597.64 2001 618.54 2002 677.3 2003 698.1 2004 697.16 2005 718.3 2006 751.64 2007 780.91 2008 824.26 2009 855.66 2010 880.16 2011 916.38 2012 947.29 2013 987.97 2014 1013.55 2015 1046.08 2016 1080.09