53% (1976)

56% (1992)

47% (1977)

64% (1980)

54% (1988)

54% (1981)

49% (1993)

55% (1980)

55% (1982)

68% (2004)

51% (1979)

52% (1979)

55% (1987)

49% (1975)

53% (1980)

70% (1974)

56% (1979)

54% (1988)

57% (1981)

51% (1978)