Year Number of 1990 615.76 1991 634.49 1992 626.13 1993 675.75 1994 680.95 1995 656.63 1996 607.9 1997 569.29 1998 553.69 1999 541.93 2000 525.07 2001 544.09 2002 532.02 2003 523.54 2004 519.44 2005 543.84 2006 543.57 2007 558.81 2008 514.17 2009 466.35 2010 467.14 2011 452.95 2012 444.05 2013 443.87 2014 424.07 2015 417.24 2016 414.72