55% (1993)

57% (1986)

58% (1997)

57% (1991)

65% (1990)

57% (1973)

63% (1971)

63% (2006)

64% (1988)

70% (1974)

63% (1987)

75% (1979)

64% (1998)

63% (1973)

58% (2000)

52% (1991)

47% (2009)

67% (1997)

60% (2016)

57% (2010)