51% (1962)

60% (1980)

64% (1976)

62% (1991)

40% (1974)

53% (1977)

51% (1972)

62% (1997)

54% (2008)

40% (1982)

56% (1968)

48% (1988)

0% (2002)

61% (1970)

54% (1986)

58% (1991)

75% (1959)

55% (1972)

56% (1985)

68% (2020)