76% (2000)

65% (1999)

59% (1997)

61% (2000)

59% (1998)

69% (2000)

61% (1999)

72% (1999)

56% (2000)

60% (1998)

61% (1999)

70% (1996)

65% (1997)

58% (1998)

59% (1999)

63% (1997)

60% (2001)

63% (2000)

56% (2000)

50% (2001)