64% (1977)

50% (1984)

64% (1975)

51% (1989)

43% (1986)

47% (1977)

61% (1975)

46% (1989)

36% (1990)

49% (1992)

38% (1973)

32% (1998)

40% (1970)

61% (1998)

61% (1975)

45% (1984)

73% (2001)

61% (1975)

0% (1971)

35% (1996)