1981 03 99.99 -99.99  26.20 
1981 04 99.99 -99.99  26.50 
1981 05 99.99 -99.99  26.70 
1981 07 99.99 -99.99  25.80 
1981 08 99.99 -99.99  25.40 
1981 09 99.99 -99.99  25.70 
1981 10 99.99 -99.99  26.40 
1981 11 99.99 -99.99  25.50 
1981 12 99.99 -99.99  25.90 
1982 02 99.99 -99.99  26.00 
1982 06 99.99 -99.99  26.10 
1982 11 99.99 -99.99  26.00 
1982 12 99.99 -99.99  25.70 
1983 01 99.99 -99.99  25.80 
1983 02 99.99 -99.99  26.10 
1983 03 99.99 -99.99  26.30 
1983 04 99.99 -99.99  26.80 
1983 05 99.99 -99.99  26.40 
1983 06 99.99 -99.99  26.30 
1983 08 99.99 -99.99  26.40 
1983 11 99.99 -99.99  25.40 
1983 12 99.99 -99.99  25.30 
1984 02 99.99 -99.99  25.20 
1984 03 99.99 -99.99  25.60 
1984 05 99.99 -99.99  25.80 
1984 06 99.99 -99.99  25.70 
1984 07 99.99 -99.99  25.70 
1984 08 99.99 -99.99  25.60 
1984 09 99.99 -99.99  25.60 
1985 10 99.99 -99.99  27.60 
1990 02 99.99 -99.99  26.20 
1990 04 99.99 -99.99  26.50 
