50% (1996)

49% (1999)

62% (1989)

58% (1997)

46% (2000)

53% (1989)

46% (1996)

54% (1994)

61% (1997)

64% (1990)

52% (1994)

55% (2004)

63% (1989)

62% (1994)

54% (2003)

0% (1970)