Year Number of 1990 5431.25 1991 5582.01 1992 5726.69 1993 5862.01 1994 5988.85 1995 6124.73 1996 6292.08 1997 6426.8 1998 6621.9 1999 6804.37 2000 7034.63 2001 7127.1 2002 7226.65 2003 7347.7 2004 7386.87 2005 7512.01 2006 7936.07 2007 8286.19 2008 8594.52 2009 8938.58 2010 9205.89 2011 9278.71 2012 9377.45 2013 9436.62 2014 9575.17 2015 9722.11 2016 9872.87