53% (1976)

56% (1992)

54% (1981)

55% (1980)

54% (1988)

55% (1987)

47% (1977)

49% (1975)

53% (1980)

68% (2004)

49% (1993)

64% (1980)

70% (1974)

52% (1979)

55% (1982)

56% (1979)

51% (1979)

51% (1978)

57% (1981)

54% (1986)