Data For August-November 1914 Was Straight Line Interpolated Since The Exchange Was Closed. Source: Standard And Poor'S, Trade And Securities Statistics: Security Price Index Record, 1964; Current Statistics, March 1964.
This NBER data series m13048 appears on the NBER website in Chapter 13 at http://www.nber.org/databases/macrohistory/contents/chapter13.html.
NBER Indicator: m13048
Release: NBER Macrohistory Database
National Bureau of Economic Research, Dividend Yield of Preferred Stock On The New York Stock Exchange for United States [M13048USM156NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M13048USM156NNBR/, July 5, 2015.