56% (1990)

51% (1984)

59% (1991)

58% (1984)

46% (1988)

67% (1979)

51% (1981)

62% (1997)

34% (1994)

48% (1983)

54% (1986)

55% (1987)

59% (1990)

47% (1980)

56% (1981)

54% (1990)

62% (1987)

51% (1996)

56% (1989)

49% (1997)