65% (1999)

70% (2001)

72% (2004)

70% (1992)

72% (1992)

64% (1989)

68% (1986)

63% (1997)

60% (1990)

70% (2005)

55% (2008)

63% (1988)

56% (1991)

57% (1990)

63% (1988)

56% (1996)

61% (2009)

45% (2008)

53% (2003)

69% (1993)