1955 10 99.99 -99.99  26.90 
1955 11 99.99 -99.99  27.20 
1955 12 99.99 -99.99  27.10 
1956 01 99.99 -99.99  27.20 
1956 02 99.99 -99.99  27.60 
1956 03 99.99 -99.99  27.20 
1956 04 99.99 -99.99  27.40 
1956 05 99.99 -99.99  26.50 
1956 06 99.99 -99.99  25.80 
1956 07 99.99 -99.99  25.30 
1956 08 99.99 -99.99  25.60 
1956 09 99.99 -99.99  26.10 
1956 10 99.99 -99.99  26.30 
1956 11 99.99 -99.99  26.60 
1956 12 99.99 -99.99  27.50 
1957 01 99.99 -99.99  28.00 
1957 02 99.99 -99.99  28.40 
1957 03 99.99 -99.99  28.50 
1957 04 99.99 -99.99  28.60 
1958 04 99.99 -99.99  28.40 
1958 05 99.99 -99.99  28.30 
1958 06 99.99 -99.99  27.40 
1958 07 99.99 -99.99  26.80 
1958 08 99.99 -99.99  26.20 
1958 09 99.99 -99.99  26.80 
1958 10 99.99 -99.99  26.90 
1958 11 99.99 -99.99  27.20 
1958 12 99.99 -99.99  27.30 
1959 01 99.99 -99.99  27.60 
1959 02 99.99 -99.99  28.20 
1959 03 99.99 -99.99  29.30 
1959 04 99.99 -99.99  29.30 
1959 05 99.99 -99.99  28.80 
1959 06 99.99 -99.99  28.20 
1959 07 99.99 -99.99  27.30 
1959 08 99.99 -99.99  26.40 
1959 09 99.99 -99.99  26.90 
1959 10 99.99 -99.99  27.30 
1959 11 99.99 -99.99  28.10 
1959 12 99.99 -99.99  27.70 
1960 01 99.99 -99.99  27.80 
1960 02 99.99 -99.99  28.30 
1960 03 99.99 -99.99  28.60 
1960 04 99.99 -99.99  29.00 
1960 05 99.99 -99.99  27.90 
1960 06 99.99 -99.99  27.10 
1960 07 99.99 -99.99  26.90 
1960 08 99.99 -99.99  27.10 
1960 09 99.99 -99.99  26.80 
1960 10 99.99 -99.99  27.60 
1960 11 99.99 -99.99  27.90 
1960 12 99.99 -99.99  28.60 
1961 02 99.99 -99.99  28.10 
