73% (2008)

63% (1996)

77% (2010)

67% (2011)

71% (1988)

67% (1977)

50% (1993)

50% (1998)

50% (1986)

60% (1976)

57% (1985)

50% (1997)

45% (1975)

0% (1978)

50% (1986)

64% (1980)

50% (1983)

62% (1990)

50% (1992)

80% (1982)