50% (1990)

56% (1997)

52% (1995)

56% (1999)

57% (2004)

53% (1985)

53% (1988)

49% (1995)

57% (1990)

62% (1991)

52% (1991)

39% (1996)

58% (1987)

57% (1989)

61% (2001)

60% (1987)

62% (1989)

57% (1993)

47% (1990)

32% (1994)