Year Number of 1990 216.69 1991 216.81 1992 220.74 1993 225.05 1994 231.61 1995 234.08 1996 234.86 1997 237.51 1998 258.31 1999 273.99 2000 315.67 2001 319.94 2002 336.27 2003 367.38 2004 373.27 2005 382.56 2006 377.69 2007 380.76 2008 398.59 2009 395.08 2010 403.09 2011 393.14 2012 395.98 2013 402.05 2014 400.19 2015 397.94 2016 394.33