1920    1 18.3800                         
1920    2 17.5400                         
1920    3 20.5100                         
1920    4 20.2200                         
1920    5 21.2100                         
1920    6 20.8200                         
1920    7 22.8800                         
1920    8 24.3700                         
1920    9 23.3000                         
1920   10 23.1300                         
1920   11 21.5500                         
1920   12 22.3700                         
1921    1 23.3900                         
1921    2 20.9900                         
1921    3 23.9500                         
1921    4 21.7800                         
1921    5 21.6700                         
1921    6 21.6800                         
1921    7 21.5300                         
1921    8 24.2200                         
1921    9 21.7600                         
1921   10 21.9900                         
1921   11 21.6900                         
1921   12 22.3800                         
1922    1 20.8500                         
1922    2 19.8200                         
1922    3 21.1200                         
1922    4 20.7000                         
1922    5 21.2100                         
1922    6 20.2500                         
1922    7 20.7200                         
1922    8 23.1300                         
1922    9 21.9200                         
1922   10 22.1500                         
1922   11 21.9400                         
1922   12 22.3900                         
1923    1 22.2900                         
1923    2 19.7700                         
1923    3 22.3400                         
1923    4 21.2700                         
1923    5 22.3100                         
1923    6 20.7900                         
1923    7 20.9400                         
1923    8 24.0400                         
1923    9 22.2900                         
1923   10 23.0800                         
1923   11 21.1600                         
1923   12 22.7400