Year Number of 1990 248.3 1991 255.67 1992 275.05 1993 303.78 1994 326.51 1995 327.72 1996 318.3 1997 316.86 1998 323.16 1999 329.09 2000 345.07 2001 346.93 2002 348.19 2003 343.48 2004 344.71 2005 330.53 2006 321.94 2007 309.95 2008 295.63 2009 290.71 2010 288.65 2011 288.78 2012 290.11 2013 298.01 2014 303.93 2015 307.5 2016 312.07