bicoal
Bituminous Coal Production in USA
Description
The bicoal.tons data set is a time series that contains the production of bituminous coal in millions of net tons per year, for the years 1920-1968.
Source
U.S. Bureau of Mines.
The data are also in Tukey, J.W. (1977).
Exploratory Data Analysis.
Massachusetts: Addison-Wesley Publishing Co.