71% (1988)

70% (1989)

73% (1986)

69% (1990)

74% (1990)

69% (1983)

69% (1991)

70% (1985)

58% (1986)

51% (1990)

67% (1987)

64% (1982)

69% (1981)

57% (1987)

10% (1996)

45% (1987)

35% (1985)

60% (1995)

67% (1989)

33% (1997)