61% (1999)

32% (1998)

42% (1996)

36% (1995)

54% (1991)

51% (1995)

50% (1992)

52% (1992)

41% (1994)

52% (1994)

50% (1993)

48% (1993)

56% (1994)

54% (1996)

45% (1993)

50% (1995)

48% (1998)

44% (1996)

61% (1993)

38% (1992)