59% (1968)

66% (1994)

49% (1983)

43% (1999)

64% (1974)

61% (2003)

53% (1973)

53% (1996)

60% (2006)

56% (1975)

60% (1997)

54% (1974)

49% (1974)

60% (1991)

60% (1976)

66% (1973)

56% (1980)

65% (1977)

45% (1993)

50% (1977)