Data From The 1926 And 1927 Volumes Of The Statistiches Jahrbuch Overlap For The First Six Months Of 1926. There Is No Absolute Assurance That Data From The Earlier Volume Are Comparable With That From The 1927 Volume. Differing Data For 1924-1927 Can Be Found In The Rear Of The 1927 Volume Of The Statistiches Jahrbuch. These Data Have Apparantly Been Revised. Beginning In March 1935 Data Include The Saar. Source: Statistiches Jahrbuch Fur Das Deutsche Reich, Tables In Rear Of Volumes 1924/5, 1926, And Following Annually (Data Through 1924 May Also Be Found In Wirtschaft Und Statistik.)
This NBER data series m03072 appears on the NBER website in Chapter 3 at http://www.nber.org/databases/macrohistory/contents/chapter03.html.
NBER Indicator: m03072
Release: NBER Macrohistory Database
National Bureau of Economic Research, Revenue Ton-Kilometers, Reichsbahn for Germany [M03072DEM453NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M03072DEM453NNBR/, September 2, 2015.