Year Number of 1990 390.68 1991 380.61 1992 368.45 1993 343.56 1994 315.34 1995 287.54 1996 264.56 1997 259.01 1998 260.21 1999 261.46 2000 264.25 2001 264.27 2002 274.9 2003 294.34 2004 306.65 2005 283.15 2006 260.67 2007 248.46 2008 253.71 2009 259.16 2010 264.5 2011 266.24 2012 272.13 2013 264.83 2014 264.09 2015 254.6 2016 247.24