Year % of total 1960 89.82300884955751 1961 88.73873873873875 1962 88.73873873873875 1963 88.93617021276596 1964 88.8888888888889 1965 94.58874458874459 1966 94.45628997867803 1967 87.95811518324608 1968 222.72727272727272 1969 79.10447761194031 1970 90.75630252100841 1971 91.0569105691057 1972 88.41309823677582 1973 90.54373522458629 1974 91.08910891089108 1975 93.03977272727273 1976 89.25619834710744 1977 92.64705882352939 1978 93.16596931659693 1979 93.42604298356511 1980 94.20131291028446 1981 94.32703003337042 1982 94.11764705882352 1983 92.47910863509749 1984 94.23503325942349 1985 92.46575342465754 1986 93.11294765840219 1987 92.37668161434979 1988 92.37967914438502 1989 94.44444444444446 1990 126.06296137339055 1991 135.97802575107295 1992 123.56505836575874 1993 130.98524 1994 134.87816091954022 1995 110.80717391304347 1996 111.01122866894198 1997 86.93417445482866 1998 80.36841666666666 1999 80.56287878787879 2000 80.56561576354679 2001 80.01476404494382 2002 74.46091703056769 2003 85.26387527839644 2004 67.62519480519481 2005 72.43456790123457 2006 50.69281867145422 2007 46.42895161290323 2008 45.894796875 2009 34.464285714285715 2010 71.04486486486486 2011 66.75199471598415 2012 63.01734584450402 2013 61.62024968789014 2014 66.87889148191366 2015 73.97224137931035 2016 68.86714717741935