Year % of total 1960 0 1961 0 1962 0 1963 0 1964 9.67741935483871 1965 18.181818181818183 1966 21.09375 1967 8.771929824561402 1968 19.402985074626866 1969 2.452316076294278 1970 2.8124999999999996 1971 10.294117647058824 1972 12.5 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 0 1994 0 1995 0 1996 0 1997 0 1998 0 1999 0 2000 0 2001 0 2002 0 2003 0 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0.6202114164904862 2010 1.0434552845528455 2011 1.1304816955684007 2012 1.1501660516605166 2013 3.680143369175627 2014 14.435701357466064 2015 27.01100233100233 2016 27.11357575757576