70% (1981)

65% (1983)

61% (1990)

77% (1986)

54% (1994)

50% (1988)

58% (1988)

62% (1990)

51% (1991)

59% (1988)

58% (1984)

59% (1986)

73% (1982)

67% (1990)

73% (1986)

70% (1994)

68% (1984)

61% (1988)

68% (1983)

50% (1989)