66% (2005)

47% (2002)

41% (2000)

48% (1990)

48% (1991)

60% (1991)

38% (1987)

53% (1992)

43% (1998)

70% (1994)

42% (1988)

50% (1985)

42% (1999)

40% (2002)

35% (2005)

0% (1996)