Year Number of 1990 183.16 1991 186.51 1992 205.88 1993 208.07 1994 215.63 1995 201.93 1996 198.13 1997 192.82 1998 192.77 1999 199.37 2000 203.75 2001 207.94 2002 217.28 2003 234.26 2004 245.26 2005 252.42 2006 260.7 2007 267.27 2008 284.64 2009 291.41 2010 302.47 2011 305.85 2012 315.37 2013 326.88 2014 338.95 2015 353.15 2016 360.14