51% (1978)

58% (1983)

67% (1992)

56% (1977)

59% (1981)

46% (1979)

64% (1982)

61% (1982)

60% (1991)

63% (1984)

60% (1975)

50% (1989)

50% (1996)

52% (1986)

58% (1990)

55% (2001)

46% (1980)

0% (2000)

50% (1994)

70% (1994)