55% (1987)

60% (1986)

61% (1984)

62% (1977)

63% (1979)

49% (1986)

57% (1988)

56% (1986)

63% (1987)

50% (1984)

65% (1978)

49% (1983)

60% (1986)

54% (1983)

55% (1989)

53% (1984)

67% (1988)

53% (1988)

36% (1985)

63% (1983)