69% (1992)

59% (1990)

73% (1993)

59% (1989)

74% (1999)

74% (1986)

74% (1994)

64% (1992)

64% (2000)

59% (1994)

67% (1987)

67% (1990)

58% (1988)

67% (1995)

67% (1995)

63% (1992)

64% (1998)

67% (1995)

63% (1988)

73% (1999)