70% (1974)

72% (1984)

63% (1996)

57% (1988)

75% (2005)

73% (1983)

71% (2002)

70% (2000)

77% (1980)

30% (1998)

80% (1995)

60% (1991)

73% (1992)

50% (1987)

60% (1988)

58% (2003)

64% (1980)

75% (1991)

80% (1997)

79% (1982)