64% (1975)

64% (1977)

61% (1975)

50% (1984)

47% (1977)

36% (1990)

45% (1984)

38% (1973)

61% (1975)

43% (1986)

44% (1989)

40% (1970)

50% (1989)

73% (2001)

47% (1992)

32% (1998)

10% (1970)

23% (1973)

40% (1969)

61% (1975)