68% (1988)

58% (1990)

67% (1986)

64% (1981)

60% (2008)

66% (1999)

64% (1991)

72% (1996)

35% (2006)

42% (1957)

58% (1997)

47% (1993)

44% (1992)

68% (1983)

60% (1988)

48% (1983)

43% (1998)

60% (1986)

45% (1993)

53% (1992)