64% (1980)

71% (1986)

71% (1981)

66% (1996)

70% (1984)

72% (1992)

73% (1989)

61% (2009)

61% (2013)

71% (1990)

75% (2016)

55% (1987)

65% (1995)

66% (2002)

62% (1999)

70% (1999)

55% (1991)

60% (1980)

69% (1987)

50% (1994)