68% (1988)

70% (1997)

57% (1997)

65% (1988)

61% (1995)

62% (1996)

67% (1988)

68% (1997)

61% (1999)

75% (1991)

47% (1989)

64% (1996)

45% (1996)

63% (1997)

65% (1996)

54% (1988)

63% (1993)

46% (1996)

47% (1993)

64% (1994)