Year Number of 1990 3557.69 1991 3779.31 1992 4057.49 1993 4308.45 1994 4616.23 1995 4938.19 1996 5165.67 1997 5377.66 1998 5650.77 1999 5931.53 2000 6190.57 2001 6414.52 2002 6622.47 2003 6802.62 2004 6983.74 2005 7119.44 2006 7161.27 2007 7260.77 2008 7335.47 2009 7443.81 2010 7565.71 2011 7696.28 2012 7817.86 2013 8060.64 2014 8291.42 2015 8538.37 2016 8800.46