62% (1976)

61% (1982)

61% (1995)

53% (1999)

63% (1977)

69% (1976)

68% (1993)

61% (1981)

62% (1974)

70% (1995)

61% (1972)

57% (2007)

62% (1988)

59% (1976)

64% (1996)

57% (2001)

67% (1974)

47% (1975)

66% (2007)

52% (1972)