61% (2009)

61% (2013)

71% (1986)

63% (1980)

71% (1984)

71% (1981)

71% (1992)

67% (1996)

64% (2002)

72% (1989)

65% (1995)

68% (2003)

70% (1999)

62% (1999)

55% (1987)

60% (1980)

71% (1990)

56% (1991)

50% (1994)

0% (2001)