52% (1980)

60% (1985)

71% (2003)

56% (1982)

58% (1989)

55% (2002)

69% (2004)

50% (1979)

66% (1995)

42% (1971)

61% (1983)

41% (1981)

56% (1976)

35% (1989)

40% (1988)

40% (1989)

33% (1974)

55% (1990)

42% (1972)

60% (1977)