67% (1984)

56% (1982)

71% (1976)

65% (1995)

53% (1976)

69% (1985)

71% (1983)

59% (1977)

46% (1983)

55% (1990)

56% (1996)

70% (1981)

54% (1976)

56% (1978)

68% (2001)

62% (2007)

62% (1977)

71% (2002)

61% (1978)

56% (1985)