1973 01 99.99 -99.99  11.70 
1973 02 99.99 -99.99  16.20 
1973 03 99.99 -99.99  19.79 
1973 04 99.99 -99.99  28.30 
1973 05 99.99 -99.99  32.80 
1973 06 99.99 -99.99  36.09 
1973 07 99.99 -99.99  33.70 
1973 08 99.99 -99.99  30.90 
1973 09 99.99 -99.99  31.10 
1973 10 99.99 -99.99  25.60 
1973 11 99.99 -99.99  18.90 
1973 12 99.99 -99.99  12.50 
1974 01 99.99 -99.99  12.10 
1974 02 99.99 -99.99  13.10 
1974 03 99.99 -99.99  22.30 
1974 04 99.99 -99.99  28.70 
1974 05 99.99 -99.99  32.09 
1974 06 99.99 -99.99  33.70 
1974 07 99.99 -99.99  33.20 
1974 08 99.99 -99.99  33.09 
1974 09 99.99 -99.99  31.20 
1974 10 99.99 -99.99  24.90 
1974 11 99.99 -99.99  18.50 
1974 12 99.99 -99.99  12.90 
1975 01 99.99 -99.99  12.00 
1975 02 99.99 -99.99  13.70 
1975 03 99.99 -99.99  19.50 
1975 04 99.99 -99.99  26.50 
1975 05 99.99 -99.99  32.59 
1975 06 99.99 -99.99  33.50 
1975 07 99.99 -99.99  31.30 
1975 08 99.99 -99.99  32.20 
1975 09 99.99 -99.99  29.80 
1975 10 99.99 -99.99  26.40 
1975 11 99.99 -99.99  18.70 
1975 12 99.99 -99.99  14.90 
1976 01 99.99 -99.99  13.10 
1976 02 99.99 -99.99  15.10 
1976 03 99.99 -99.99  19.10 
1976 04 99.99 -99.99  26.70 
1976 05 99.99 -99.99  32.09 
1976 06 99.99 -99.99  33.09 
1976 07 99.99 -99.99  33.30 
1976 08 99.99 -99.99  30.50 
1976 09 99.99 -99.99  29.70 
1976 10 99.99 -99.99  26.50 
1976 11 99.99 -99.99  18.50 
1976 12 99.99 -99.99  13.40 
1977 01 99.99 -99.99  12.70 
1977 02 99.99 -99.99  15.70 
1977 03 99.99 -99.99  23.10 
1977 04 99.99 -99.99  27.10 
1977 05 99.99 -99.99  30.70 
1977 06 99.99 -99.99  33.09 
1977 07 99.99 -99.99  33.30 
1977 08 99.99 -99.99  33.00 
1977 09 99.99 -99.99  30.10 
1977 10 99.99 -99.99  27.50 
1977 11 99.99 -99.99  21.60 
1977 12 99.99 -99.99  15.10 
1978 01 99.99 -99.99  11.90 
1978 02 99.99 -99.99  14.70 
1978 03 99.99 -99.99  19.00 
1978 05 99.99 -99.99  35.30 
1978 06 99.99 -99.99  37.50 
1978 07 99.99 -99.99  30.70 
1978 09 99.99 -99.99  29.90 
1978 10 99.99 -99.99  26.30 
1978 11 99.99 -99.99  19.50 
1978 12 99.99 -99.99  14.60 
