68% (1989)

70% (1985)

66% (1981)

65% (1984)

56% (1986)

50% (1992)

55% (1991)

49% (1994)

62% (1986)

60% (1987)

58% (1989)

48% (1995)

50% (1993)

61% (1988)

66% (1984)

62% (1989)

48% (1987)

62% (1980)

57% (1995)

50% (1987)