Series Is Presented Here As Two Variables--(1)--Original Data, 1919-1930 (2)--Original Data, 1930-1968. Source: NBER Computed Data By Subtracting Total Seperation Rate From Gross Accession Rate (Series 08255); Data Are From Bureau Of Labor Statistics.
This NBER data series m08256a appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08256a
Release: NBER Macrohistory Database
National Bureau of Economic Research, Labor Turnover, Net Accession Rate, Manufacturing for United States [M0856AUSM498NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M0856AUSM498NNBR/, August 29, 2015.