54% (1992)

68% (1997)

62% (1995)

61% (1991)

58% (1993)

53% (1995)

54% (1996)

55% (1996)

51% (1994)

57% (1991)

49% (1997)

65% (1995)

41% (1998)

55% (1993)

58% (1994)

66% (1998)

61% (1997)

60% (1992)

50% (1995)

52% (1994)