Year Number of 1990 440.56 1991 459.07 1992 478.96 1993 500.37 1994 522.87 1995 546.58 1996 555.72 1997 565.25 1998 575.02 1999 585.09 2000 595.65 2001 612.34 2002 630.23 2003 652.59 2004 675.22 2005 697.12 2006 714.84 2007 732.38 2008 753.13 2009 775.92 2010 801.45 2011 822.07 2012 845 2013 866.88 2014 890.13 2015 914.59 2016 939.35