55% (1982)

54% (1981)

49% (1989)

58% (1980)

64% (1968)

55% (1987)

57% (1981)

51% (1978)

64% (1980)

47% (1977)

53% (1988)

53% (1980)

65% (2002)

70% (1977)

57% (1975)

46% (1986)

72% (1973)

75% (1974)

55% (1980)

51% (1979)