58% (1988)

71% (1977)

59% (1976)

52% (1970)

30% (1980)

48% (1989)

48% (1969)

41% (1971)

35% (1968)

59% (1967)

0% (1992)

51% (1965)

54% (1987)

46% (1991)

61% (1972)

68% (1974)

60% (1993)

75% (1981)

57% (1975)

59% (1993)