57% (1986)

67% (1980)

65% (1983)

61% (1985)

61% (1990)

61% (1988)

59% (1990)

47% (1991)

59% (1993)

55% (1987)

53% (1987)

58% (1985)

67% (1981)

57% (1991)

57% (1983)

59% (1989)

61% (1993)

57% (1987)

56% (1982)

44% (1988)