63% (1992)

59% (1999)

62% (1988)

67% (1998)

67% (1997)

58% (1996)

63% (1977)

72% (1989)

70% (1979)

66% (1982)

80% (1984)

65% (2000)

62% (1990)

70% (1979)

55% (2000)

70% (1981)

64% (1986)

61% (1994)

72% (1982)

57% (1998)