73% (1975)

48% (1973)

56% (1975)

63% (1974)

59% (1970)

59% (1991)

46% (1973)

30% (1974)

42% (1988)

77% (1969)

53% (1974)

52% (1983)

60% (1973)

50% (1969)

58% (1996)

54% (1971)

43% (1993)

63% (1974)

46% (1997)

59% (2006)