Year Number of 1990 198.89 1991 204.17 1992 210.51 1993 216.91 1994 226.12 1995 234.61 1996 241.51 1997 254.49 1998 265.67 1999 275.42 2000 287.78 2001 292.14 2002 298.54 2003 303.79 2004 311.08 2005 320.66 2006 324.85 2007 330.77 2008 336.31 2009 342.63 2010 353.39 2011 363.55 2012 373.36 2013 384.11 2014 393.91 2015 404.94 2016 418.13