Year Number of 1990 5252.75 1991 5612.11 1992 5952.81 1993 6107.44 1994 6336.87 1995 6683.47 1996 6566.32 1997 6320.75 1998 6065.83 1999 6298.03 2000 6497.31 2001 6458.61 2002 6478.49 2003 6531.21 2004 6665.85 2005 6846.07 2006 6644.28 2007 6884.33 2008 6958.78 2009 6353.36 2010 6161.75 2011 6056.48 2012 6232.27 2013 6240.65 2014 6107.26 2015 6199.78 2016 6326.28