"Year","From early to mid career","From early to late career","From mid to late career"
1914,,,1.482213
1915,,,1.909775
1916,,,2.369399
1917,,,2.438714
1918,,,2.077736
1919,,,2.101781
1920,,,2.263780
1921,,,1.741742
1922,,,2.101911
1923,,,1.954603
1924,,,2.326322
1925,,,2.064602
1926,2.193121,3.849782,2.040816
1927,2.316708,4.666432,1.875617
1928,2.709232,5.818891,2.324798
1929,2.813642,6.005619,1.774744
1930,2.398969,5.476858,2.317114
1931,2.20004,5.647424,1.840708
1932,2.746414,6.286187,2.128414
1933,3.072289,5.825243,2.198991
1934,2.643812,6.091954,3.113110
1935,3.253671,6.549886,2.715232
1936,2.954545,7.348597,2.587619
1937,2.828854,6.227106,2.51938
1938,2.450067,6.371866,2.417649
1939,1.944809,5.2376,2.529303
1940,2.570502,6.512537,2.577622
1941,2.967431,7.844368,2.298206
1942,2.752868,6.661162,2.727943
1943,3.119303,7.097957,2.192362
1944,3.312102,7.512383,2.759980
1945,3.062099,7.317857,3.030596
1946,3.565156,7.603623,2.542985
1947,3.713611,8.133993,2.660506
1948,3.627630,8.704946,2.931262
1949,3.460899,8.429356,2.950619
1950,3.704934,8.566247,2.646489
1951,3.330264,,
1952,3.723019,,
1953,3.331927,,
1954,3.393240,,
1955,3.169060,,
1956,3.444431,,
1957,3.548963,,
1958,3.426429,,
1959,3.339858,,
1960,3.286857,,
1961,3.481634,,
1962,3.559796,,