59% (1990)

64% (1991)

57% (1990)

63% (1996)

66% (1997)

52% (1995)

62% (1989)

61% (1987)

53% (1989)

61% (1994)

53% (1995)

45% (1995)

52% (1994)

62% (1995)

46% (1992)

64% (1998)

51% (1992)

62% (1991)

42% (1989)

54% (1996)