58% (1987)

72% (1992)

61% (1987)

60% (2010)

54% (1997)

58% (1991)

56% (2001)

66% (1994)

61% (1997)

54% (2010)

67% (2001)

57% (2008)

63% (1989)

52% (1994)

58% (1991)

56% (1991)

53% (1995)

64% (1991)

68% (2012)

62% (2008)