Year Number of 1990 277.77 1991 281.58 1992 279.72 1993 304.39 1994 312.28 1995 317.34 1996 328.02 1997 331.34 1998 339.51 1999 346.74 2000 347.99 2001 350.13 2002 355.53 2003 358.56 2004 361.03 2005 364.98 2006 369.18 2007 369.4 2008 368.5 2009 372.37 2010 382.76 2011 387.12 2012 386.33 2013 395.87 2014 401.55 2015 409.31 2016 417.35