1977 01 99.99 -99.99   5.20 
1977 02 99.99 -99.99  10.10 
1977 03 99.99 -99.99  19.10 
1977 04 99.99 -99.99  23.00 
1977 05 99.99 -99.99  26.20 
1977 06 99.99 -99.99  31.70 
1977 08 99.99 -99.99  30.00 
1977 09 99.99 -99.99  22.30 
1977 10 99.99 -99.99  20.80 
1978 01 99.99 -99.99   6.50 
1978 02 99.99 -99.99   9.60 
1978 03 99.99 -99.99  12.90 
1978 04 99.99 -99.99  21.40 
1978 05 99.99 -99.99  26.50 
1978 06 99.99 -99.99  30.60 
1978 07 99.99 -99.99  33.30 
1978 08 99.99 -99.99  29.50 
1978 09 99.99 -99.99  23.90 
1978 10 99.99 -99.99  17.40 
1978 11 99.99 -99.99  11.80 
1978 12 99.99 -99.99  10.90 
1979 01 99.99 -99.99   7.70 
1979 02 99.99 -99.99   9.39 
1979 03 99.99 -99.99  11.60 
1979 04 99.99 -99.99  21.80 
1979 05 99.99 -99.99  23.90 
1979 06 99.99 -99.99  30.10 
1979 07 99.99 -99.99  32.00 
1979 08 99.99 -99.99  28.00 
1979 09 99.99 -99.99  24.00 
1979 10 99.99 -99.99  19.50 
1979 11 99.99 -99.99   9.50 
1979 12 99.99 -99.99   8.00 
1980 01 99.99 -99.99   6.80 
1980 02 99.99 -99.99   8.80 
1980 03 99.99 -99.99  13.40 
1980 04 99.99 -99.99  22.10 
1980 05 99.99 -99.99  26.60 
1980 06 99.99 -99.99  30.20 
1980 07 99.99 -99.99  32.20 
1980 08 99.99 -99.99  29.60 
1980 09 99.99 -99.99  23.70 
1980 10 99.99 -99.99  20.20 
1980 11 99.99 -99.99  14.10 
1980 12 99.99 -99.99   9.50 
