72% (2002)

66% (2000)

58% (2004)

52% (1997)

59% (1990)

79% (1993)

69% (1989)

60% (1989)

63% (1992)

60% (1986)

60% (1995)

54% (1991)

67% (1994)

50% (1984)

50% (1993)

35% (1999)

71% (1993)

55% (1994)

65% (1991)

70% (1990)