Year Number 1974 36.7541 1975 35.56716 1976 38.33333 1977 36.92308 1979 35.07692 1986 29.06977 1987 27.97674 1988 26.24242 1990 24.62921 1991 22.46 1992 18.51852 1993 22.90076 1999 18.31429 2000 14.99275 2001 17.69231 2002 15.88148 2003 11.91111 2004 13.42222 2005 14.04575 2006 13.90345 2007 13.83824 2008 14.85926 2009 13.50714 2010 13.80292 2011 10.7929 2012 10.8375 2013 12.53691 2014 12.89063 2015 11.35333 2016 11.27027