72% (1968)

70% (1992)

62% (2016)

53% (2010)

56% (2006)

49% (1997)

64% (1991)

63% (1975)

67% (1958)

65% (2011)

63% (2009)

62% (1968)

58% (2001)

71% (1989)

72% (1998)

71% (1994)

65% (2012)

73% (1995)

70% (1993)

74% (1996)