80% (1980)

74% (1986)

69% (1987)

61% (1995)

66% (1993)

68% (1981)

57% (1989)

62% (2005)

68% (1983)

67% (1982)

71% (1987)

69% (1982)

56% (1991)

53% (1986)

60% (1992)

57% (1980)

37% (1978)

65% (1984)

0% (1970)

68% (2015)