1968 35.3 194.2 224.9 .108 74.8 1969 35.3 202.5 218.5 .116 72.8 1970 28.9 176.8 201.3 .116 65.6 1971 27.3 155.3 182.3 .104 58.9 1972 26.5 150.7 171.1 .105 55.4 1973 26.4 150.2 155.9 .109 51.1 1974 21.3 94.2 152.7 .221 47.8 1975 21.4 100.9 153.1 .367 46.0 1976 19.3 94.2 147.5 .396 45.3 1977 21.0 94.2 150.2 .433 44.8 1978 20.0 93.5 150.7 .420 43.6 1979 21.3 96.1 156.5 .437 44.9 END OF DATA