57% (1980)

54% (1973)

51% (1991)

48% (1980)

39% (1976)

20% (2002)

58% (1974)

56% (1975)

40% (1980)

41% (1983)

58% (1976)

53% (1975)

48% (1980)

54% (1984)

46% (1977)

61% (1997)

62% (1975)

33% (1976)

54% (1980)

51% (1976)