Year Number of 1990 9192.09 1991 9481.55 1992 9827.46 1993 10127.81 1994 10498.2 1995 10864.14 1996 11197.04 1997 11572.42 1998 11951.45 1999 12366.49 2000 12704.92 2001 12960.23 2002 13244.41 2003 13657.84 2004 14036.9 2005 14333.36 2006 14475.61 2007 14663.77 2008 14838 2009 14995.51 2010 15192.77 2011 15441.88 2012 15698.84 2013 16091.36 2014 16473.72 2015 16959 2016 17440.44