Year Number of 1990 7871.42 1991 7883.11 1992 7866.58 1993 7877.65 1994 7732.81 1995 7650.81 1996 7631.13 1997 7563.86 1998 7449.7 1999 7451.95 2000 7367.48 2001 7383.17 2002 7358.55 2003 7254.59 2004 7135.25 2005 6974.49 2006 6923.51 2007 6916.79 2008 6931.34 2009 6981.95 2010 6977.73 2011 6951.12 2012 6996.08 2013 7040.91 2014 7015.89 2015 7056.66 2016 7211.45