72% (1991)

74% (2001)

77% (1993)

73% (1999)

58% (1995)

61% (1994)

73% (1995)

76% (1991)

58% (1994)

62% (1992)

74% (1989)

63% (2001)

58% (2000)

65% (1993)

53% (1990)

48% (1997)

68% (1996)

56% (1992)

59% (1991)

47% (1992)