Year 	Time 
1924 	83.2 
1928 	82.2 
1932 	79.4 
1936 	78.9 
1948 	74.4 
1952 	74.3 
1956 	72.9 
1960 	69.3 
1964 	67.7 
1968 	66.2 
1972 	65.8 
1976 	61.8 
1980 	60.9
1984 	62.6
1988 	60.9
1992 	60.7