66% (1993)

52% (1991)

71% (1989)

62% (1990)

64% (1982)

68% (1986)

64% (1993)

73% (1987)

69% (1993)

61% (1991)

53% (1993)

66% (1988)

71% (1995)

71% (1992)

78% (1996)

55% (1994)

60% (1982)

72% (1973)

65% (1998)

60% (2001)