65% (1977)

46% (1984)

63% (1980)

60% (1981)

57% (1983)

61% (1982)

61% (1986)

61% (1977)

53% (1999)

62% (1978)

75% (1983)

60% (1975)

58% (1985)

54% (1998)

64% (1996)

62% (1988)

56% (1997)

63% (1983)

67% (1975)

60% (1988)