Year 	Male 	Female
1920 	  53.6 	 54.6
1930 	  58.1 	 61.6
1940 	  60.8 	 65.2
1950 	  65.6 	 71.1
1960 	  66.6 	 73.1
1970 	  67.1 	 74.7
1980 	  70.0 	 77.5
1990 	  71.8 	 78.8