Year Number of 1990 9453.21 1991 9586.07 1992 9772.79 1993 9912.47 1994 10046.19 1995 10222.98 1996 10457.01 1997 10657.76 1998 10951.7 1999 11232.13 2000 11457.46 2001 11612.76 2002 11789.19 2003 12125.36 2004 12351.64 2005 12545.54 2006 12772.19 2007 12971.29 2008 13177.07 2009 13435.87 2010 13705.35 2011 13985.33 2012 14281.66 2013 14740.52 2014 15140.12 2015 15767.26 2016 16579.06