73% (1979)

57% (1980)

74% (1982)

43% (1992)

61% (1991)

51% (1989)

77% (1988)

62% (1984)

75% (1993)

35% (1987)

69% (1981)

56% (1996)

58% (1998)

55% (1991)

83% (1979)

50% (1979)

57% (1997)

45% (1986)

75% (1985)

50% (1990)