56% (1987)

61% (2009)

71% (1986)

61% (2013)

66% (2002)

70% (1984)

71% (1981)

63% (1980)

66% (1996)

65% (1995)

73% (1989)

71% (1992)

71% (1990)

60% (2004)

55% (1991)

70% (1999)

68% (2003)

55% (1977)

61% (1997)

60% (1980)